IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 39, NO. 12, DECEMBER 2004 2269 A 3–10-GHz Low-Noise Amplifier With Wideband LC-Ladder Matching Network Aly Ismail and Asad A. Abidi, Fellow, IEEE Abstract—Reactive matching is extended to wide bandwidths using the impedance property of LC-ladder filters. In this paper, we present a systematic method to design wideband low-noise amplifiers. An SiGe amplifier with on-chip matching network spanning 3–10 GHz delivers 21-dB peak gain, 2.5-dB noise figure, and 1-dBm input IP3 at 5 GHz, with a 10-mA bias current. Index Terms—Amplifier noise, low-noise amplifier (LNA), noise figure (NF), SiGe amplifier, ultrawideband (UWB), wideband matching. Fig. 1. Spectrum allocated for UWB communication. I. INTRODUCTION W IDEBAND systems have recently received a great deal of interest due to their potential for high-speed wireless communication [1]–[3]. However, there are new challenges to be faced for a feasible transceiver implementation. Ultrawideband (UWB) is a wireless technology that transmits an extremely low-power signal over a wide swath of radio spectrum [1]–[3]. UWB systems operate across a wide range of frequencies from 3.1 to 10.6 GHz, as shown in Fig. 1. Conventional RF circuits fail to meet the needs of the UWB receiver. The dynamic range of wideband amplifiers that work well in other applications like high-speed optical transceivers may not be good enough for UWB systems. In fact, the lownoise amplifier (LNA) design is one of the biggest challenges. To interface with the antenna and preselect filter, the LNA input impedance should be close to 50 across the band from 3 to 10 GHz. The inductor-degenerated LNA used in conventional wireless receivers offers the right properties [4]–[11], but only in a narrow band around a single frequency [12]–[14]. A resistor feedback wideband amplifier cannot provide sufficiently low noise figure (NF) (2 3 dB) and high gain ( 20 dB) while consuming low power. A new methodology to extend the reactively matched LNAs to wide bandwidths is presented. It is shown that this approach satisfies the tough system requirement of a UWB system with moderate power consumption. To provide some background, Section II shows that resistive feedback amplifiers cannot provide the required performance while consuming low power. Section III briefly describes the design tradeoffs in the narrowband inductively degenerated amplifier. The concept of wideband impedance matching is introduced in Section IV and used to extend the bandwidth of the nar- Manuscript received April 19, 2004; revised July 10, 2004. A. Ismail is with Skyworks Solutions, Inc., Irvine, CA 92612 USA (e-mail: aismail@icsl.ucla.edu). A. A. Abidi is with the Integrated Circuits and Systems Laboratory, Electrical Engineering Department, University of California, Los Angeles, CA 90095 USA. Digital Object Identifier 10.1109/JSSC.2004.836344 Fig. 2. Schematic of a resistive feedback amplifier. rowband LNA. The design methodology as well as some practical considerations are discussed in Sections V and VI. Experimental results for a wideband fully integrated SiGe amplifier are presented in Section VII. II. RESISTIVE FEEDBACK AMPLIFIERS In the design of LNAs in wireless receivers, there are several common goals. These include low NF of the amplifier, reasonable gain with sufficient linearity, a stable 50- input impedance, and low power consumption, which is needed in portable systems. Satisfying all of the design goals of the UWB systems is particularly difficult because of the broad bandwidth compared to conventional wireless receivers. To demonstrate that, let us consider the resistive feedback amplifier circuit shown in Fig. 2. The input resistance is given by (1) where is the small-signal transconductance gain of the NPN transistor. The voltage gain is given by 0018-9200/04$20.00 © 2004 IEEE (2) 2270 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 39, NO. 12, DECEMBER 2004 In the absence of any other losses, this produces the LNA noise factor (6) Fig. 3. Equivalent circuit for the inductively degenerated transistor. and, neglecting the base and emitter parasitic resistance, the noise factor is given by It is noted that the noise figure improves quadratically with for a given resonance frethe transistor unity gain frequency . Clearly, due to the noiseless inductive degeneration quency , (5) and (6) are decoupled. To obtain the best noise figure, . Practically, the the transistor should be biased to the peak parasitic base and emitter resistances will degrade the obtained noise factor. Taking into account these losses, the noise factor is (7) In this case, the IIP3 is given by (3) IIP where is the 50- source resistance. The required linearity, typically measured in terms of the third-order intercept point (IIP3), is specified by IIP (4) Intuitively, the higher the , the larger the loop gain, which means more current improves linearity [19]. A larger consumption. However, for high-frequency operation, more current consumption is usually needed to drive the parasitic capacitances and obtain enough gain. This results in a little . The voltage gain given by (2) flexibility in the choice of and for a given . As a result, sets a relation between the noise factor and input resistance are coupled because, and . as shown in (1) and (3), they both depend on Because of this tradeoff, it is generally difficult to achieve an arbitrarily low noise factor for an input impedance of 50 with a reasonable current consumption [2], [20]. To achieve more design flexibility, ways to decouple the noise factor from the input impedance are needed [21], [37]. Inductor degeneration in common-emitter LNAs was introduced by Van der Ziel and Strutt to generate the real part needed to match the input impedance, resulting in an improvement in the output SNR [21]. By decoupling the input impedance from the noise factor, this topology allows the optimization of the dynamic range with reasonable power consumption [22]. Consider the circuit results in an shown in Fig. 3. The degeneration inductance equivalent input resistance given by (5) is the unity gain frequency of the transistor. The rewhere sulting equivalent circuit of the degenerated transistor consists and , as shown in Fig. 3. The input impedance of the , and . In is purely resistive at the resonance frequency of practice, an off-chip inductor is added in series to align the series resonance frequency with the desired frequency of operation. IIP IIP (8) The dynamic range of the LNA is defined as DR IIP (9) This means that, at a constant impedance match, the dynamic range is proportional to the bias current. Thus, a strong reactive feedback merely slides the dynamic range by lowering the noise can also figure and intercept point together [22]. Note that be used to trade some noise figure to IIP3 and vice versa. In some cases, the minimum degeneration inductance is limited because of packaging considerations. For a wirebond package, the minimum degeneration inductance even in the case of multiple parallel downbonds cannot be lower than around 0.5 nH because of mutual inductance. At first sight, (5) would limit to obtain a 50- input resistance the maximum allowable and thus effecting the noise factor. However, passive and elements transform down a real resistance in a narrow band of frequencies. This process is better visualized using the Smith Chart [2], [14]–[18]. As shown in Fig. 4, a transformation ratio (a) is used in the matching network to lower the input resistance to 50 . As a result, for a given degeneration inductance , the resulting noise factor is given by (10) . Note that, compared with (6), the noise where . This means that the use factor improves only linearly with of advanced packaging techniques like flip-chip, which allow lower degeneration inductances, can potentially improve further the noise figure. This also means that differential LNAs with integrated degeneration inductors have an additional degree of flexibility compared to their single-ended counterparts in wirebond packages. Recently, some narrowband differential LNAs were reported with very low noise figures at 5–6 GHz [24], [25]. ISMAIL AND ABIDI: A 3–10-GHz LNA WITH WIDEBAND LC–LADDER MATCHING NETWORK 2271 Fig. 5. Doubly terminated two-port network. Fig. 4. narrowband impedance transformation using passive elements. Alternatively, the noise factor can be expressed as Fig. 6. Second-order low-pass ladder filter section. (11) where is the quality factor of the input matching network. The because more voltage noise factor improves with a higher gain is seen across the input capacitance of the transistor. The input impedance is resistive only in a narrow bandwidth around the resonance frequency . To obtain a wideband impedance matching, the of the matching circuit should be significantly lowered. This will largely degrade the noise figure which defeats the purpose. As a result, this type of amplifier cannot be used for wideband applications. Fig. 7. Input impedance of the low-pass filter versus frequency. III. WIDEBAND IMPEDANCE MATCHING Wideband impedance matching was first introduced by Bode [26] in 1945 and Fano [27] in 1950 to enhance the bandwidth of antennas. Fano has derived a complete set of integrals that predicts the gain–bandwidth restrictions for lossless matching networks terminated in an arbitrary load impedance [27]. Fano’s broadband method is hence a natural solution to extend the bandwidth of narrowband circuits. As a result, conceptually, it should be possible to extend the bandwidth of the narrowband LNA. However, the antenna is well defined prior to the design of the matching circuit. In the course of the design of the wideband LNA, both the amplifier and the matching circuit are unknown. The matching circuit as shown previously can affect the circuit performance. In other words, the bandwidth enhancement using Fano’s broadband matching criteria of an optimally designed narrowband amplifier will not necessarily result in the optimum wideband amplifier. What is needed is a systematic methodology that will allow us to design the optimum wideband amplifier side by side with the matching circuit. To gain some insight, we turn to the ladder filters. Consider the doubly terminated two-port network with an and a load resistance shown in Fig. 5 input resistance , the [28]. We define the (input/output) transfer function loss (in nepers), and the phase (in radians) by (12) It is noted that (13) is the maximum power available from the source where and is the actual power dissipated in . In the case of impedance matching, as the two-port network elements are in the all lossless, the loss is equal to zero and passband. Under this condition, the input impedance seen from the source terminal is real and equal to . Let us consider the simple doubly terminated second-order low-pass filter shown in Fig. 6. By choosing the values of and so that (14) the input impedance is mainly resistive and equal to up to , the low-pass filter cut-off frequency in Fig. 7. In the stopband, the impedance is mainly reactive and no signal propagates through the circuit. Using the low-pass to bandpass transfor, the series inductor is mation transformed to a series LC and the shunt capacitor to a parallel LC. The fourth-order doubly terminated bandpass filter shown 2272 Fig. 8. IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 39, NO. 12, DECEMBER 2004 Fourth-order bandpass ladder filter used for impedance matching. Fig. 10. Different currents flowing in the bandpass filter. which implies that the voltage across the input capacitance of the transistor rolls off at 20 dB/decade versus frequency. The noise factor of the new amplifier is (20) Fig. 9. Input impedance of the bandpass filter versus frequency. where and are the input-referred current and voltage sources of the amplifier. The resulting noise factor expression is in Fig. 8 is obtained. Here the input impedance across the arto is uniform and equal to , as bitrary passband from shown in Fig. 9. The fractional bandwidth ( ) is defined as (15) Since , the bandpass filter can be seen as a low-pass filter section interleaved with a high-pass filter section. In this case, the matching circuit elements are chosen so that and which worsens quadratically with frequency. This is mainly because the gain from the input voltage to the drive voltage across the transistor rolls off with frequency. The IIP3 of the amplifier is equal to the IIP3 of the degenerated transistor multiplied by 2 because of the potential divider at the input across . IIP3 can be estimated by studying the feedback applied across the transistor due to the inductive degeneration [30]. , the amplifier Neglecting the effect of the nonlinearity of is hence given by (16) (17) Interestingly, the right part of the bandpass filter looks similar to the equivalent circuit of the inductively degenerated transistor in Fig. 3. Therefore, the bandpass filter can embed the inductively degenerated transistor and obtain the desired input impedance, as shown in Fig. 8. This results in a broadband impedance matching of the inductively degenerated transistor. Now let us consider the simplified circuit in Fig. 10. In the passband where impedance is matched [28], the current entering and resistive. For maxthe left port of the ladder filter is imum power transfer, all of this current must flow into the termination resistor at the right, which means that (18) From (17), this means that (19) (21) where is the loop gain due to degeneration and is the transistor thermal voltage. This means that, unlike the noise factor, IIP3 gets better with frequency. Equation (17) also implies that (22) This determines the bias current. Now, to minimize the noise factor, from (20), should be as large as possible. As shown in of the SiGe HBT is around 90 GHz. HowFig. 11, the peak of 60 GHz for two reasons. ever, the transistor is biased at an First, it is not recommended to operate the transistor at the peak current density which can markedly degrade the performance due to process variations. Second, the base resistance which is a main contributor to the noise factor is large for small transistors 3 GHz and match and is traded off with . From (22), for to 50 , the bias current will be 10 mA and is 7 . ISMAIL AND ABIDI: A 3–10-GHz LNA WITH WIDEBAND LC–LADDER MATCHING NETWORK Fig. 11. density. Plot of the unity gain frequency of the transistor versus its current 2273 Fig. 13. Plot showing the transistor IP3 dependence on the voltage headroom across it. Fig. 12. Alternative bandpass ladder filter for unequal load and source resistances. When using wirebond connections to the package, operation needs some sort of impedance transformation. Unat large fortunately, we cannot use the same impedance transformer network that is customary in narrowband amplifiers. What is required here is a doubly terminated bandpass filter with unequal loads. In a similar fashion, the amplifier will replace the series RLC in the new filter. To achieve this wideband impedance transformation between the source and load resistances, the cirand [29], as cuit should include two additional inductors shown in Fig. 12. When realized on-chip, the loss resistance of the inductors will degrade the noise figure. To obtain the best noise figure with the simplest matching circuit, it was chosen to use an on-chip degeneration inductance that leads directly to a 50- input resistance. The weak in-band signal suffers from intermodulation distortion from both in-band and out-of-band blockers. The input matching network which is a bandpass filter attenuates out-of-band blockers. The higher the filter order, the more these blockers are attenuated. Since there is no way to detune parasitic reactances, we implement the remaining matching components on-chip. To limit the extra noise contributed by inductor loss, no more than two inductors are used in the matching circuit. into account, the resulting Taking the coupling capacitor network is a fifth-order bandpass filter. In this case, in-band blockers will dominate the voltage swing across the input capacitance of the transistor and specify the amplifier IIP3. are As shown in Figs. 13 and 14, the amplifier IIP3 and across the transistor. For this reason, sensitive to the bias 1 V to obtain the best IIP3 and . Fig. 14. Plot showing the transistor f dependence on the voltage headroom across it. Fig. 15. Wideband voltage gain equalization using an inductive load. The overall amplifier gain should be flat across the passband. The output current from the transistor rolls off inversely with . An inductive load equalizes the voltage gain frequency, like to a constant value across the passband, as shown in Fig. 15. The parasitic capacitance across the inductor should be minimized should be suffito ensure self resonance beyond 10 GHz. ciently low so that the inductive region of the impedance spans the passband. 2274 Fig. 16. IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 39, NO. 12, DECEMBER 2004 Simulated noise figure versus frequency for different values of r . IV. SOME PRACTICAL CONSIDERATIONS In a typical LNA, the base parasitic resistance contributes significantly to the output noise. Taking into account, the resulting noise figure is Fig. 17. Complete schematic of the prototype LNA. Fig. 18. Die photograph of the LNA chip. (23) which means that will add noise uniformly at all frequencies. Clearly, efforts to lower the base resistance will pay off with a lower possible noise figure. Another point of considerations is related to the high-pass which is specified by and , as shown cut-off frequency is the parasitic capacitance of the pad and of in (16) and (17). is specified by the input resistance, the on-chip inductor . to a frequency higher as shown by (16) and (17). To push should be less than 300 fF. As mentioned prethan 10 GHz, viously, the quality factor of should be sufficiently high so as not to degrade the noise figure of the circuit. There is a maximum quality factor and a self-resonance frequency associated also with the optimally designed spiral implementing . causes another problem. The assumed frequency roll-off for the is 20 dB/decade. However, at the approach of , transistor the roll-off is more rapid because of the filter transition band. It beyond 10 GHz. As a is difficult in this technology to push result, the noise figure increases significantly at high frequencies, as shown in Fig. 17. Now the base resistance also affects the input resistance (24) This means that, for a higher base resistance, smaller is higher needed for matching. Thus, can be used to push since, from (17), and thus lower the in-band roll-off. As a result, higher noise figure at lower frequencies can be traded for lower noise figure at higher frequencies, as shown in Fig. 16. In this way, the signal-weighted wideband noise figure can be optimized. Another tradeoff is in the choice of the coupling capacitor . If is too large, its bottom plate capacitance will add , which effects . If it is too small, the bandpass filter to will not meet the specification on . was chosen to be the smallest possible value in order not to increase the parasitic . The load resistance of the amplifier was capacitance increased to equalize the voltage gain transfer function to a flat response. V. FINAL CIRCUIT The final wideband LNA circuit is shown in Fig. 17. The matching circuit consists of the capacitor , which is the parasitic capacitance at the input node including the pad in parallel in series with the with the on-chip spiral inductor , and on-chip spiral inductor . The cascode transistor improves reverse isolation and lowers Miller multiplied capacitance. The in seload of the amplifier consists of the on-chip inductor ries with the polysilicon resistor . An emitter follower inserted for measurement purposes only buffers the output to an external 50- resistance. This emitter follower is not present when the LNA is a part of a fully integrated UWB receiver. All of the bias voltages and currents are generated on-chip from a bandgap reference. The amplifier draws 10 mA and the emitter follower draws 15 mA from a 3-V supply. The circuit was fabricated in the Jazz Semiconductor SiGe 0.18- m BICMOS process. The die photograph is shown in Fig. 18. The total die area is 1.8 mm . All of the spiral inductors and MIM capacitors were very carefully modeled across the band of interest and compared to measurement data from test chips. Interconnects were modeled as transmission lines and ISMAIL AND ABIDI: A 3–10-GHz LNA WITH WIDEBAND LC–LADDER MATCHING NETWORK back annotated in the final simulations. The value of the spiral inductors and capacitors were adjusted to equalize the response after modeling the interconnects. Large MIM capacitors were used to ac ground the supply line and the base node of the cascode transistor. Spiral inductors were separated to lower the mutual coupling and placed close to the pads. Short interconnects connect the amplifier to the emitter follower with least parasitic capacitance. Ground was connected on metal 1 under the RF pad to prevent substrate noise from coupling to the amplifier RF input. 2275 TABLE I SUMMARY OF THE MEASUREMENT RESULTS VI. LINEARITY CONSIDERATIONS Linearity is an important measure to the ability of the circuit to handle large signals. In narrowband amplifiers, the linearity is typically described with the third-order intercept point IP3 and the 1-dB compression point (CP). A wideband circuit may need other ways of specification because one large signal can compress the gain at all frequencies [18], [19]. In a UWB receiver, the LNA encompass several subbands as well as the WLAN signals in the middle of the band spanning from 5.1 to 5.8 GHz. Equation (21) gives an estimate for the in-band IIP3. Linearity improves at higher frequency because the matching circuit amplifies less. Therefore, the worst-case linearity is at the lower end of the spectrum. Three different measurements indicate in-band and out-of-band effects. The first two measurements are the in-band IIP3 and the out-of-band CP, respectively, and they are both swept across frequency. IP3 was measured using two tones that are separated by a 100 MHz and of equal amplitude. In-band CP was measured by sweeping the amplitude of a single tone to detect the small-signal gain compression of the signal. The third measurement shows the effect of cross-band compression due to out-of-band blockers. Cross-band compression is defined as the signal power in one band that causes 1-dB degradation in the small-signal gain in another band. To measure this, the amplitude of a tone is increased to monitor the small signal gain compression of a 3.4-GHz weak tone which lies at the lower end of the spectrum. An out-of-band IP3 measurement at 5.4 and 5.6 GHz which lie in the WLAN band was added for completion and to show that the same LNA can receive both UWB and WLAN. The measurement results are shown in the next section. Due to the second-order nonlinearity of the transitor, the base current is modulated at the beat frequency between the blockers. Flowing to ground through a large low-frequency impedance from the base of the transitor, this effect worsens the nonlinearity of a bipolar LNA and degrades IIP3 [36]. Fortunately, the offers a low impedance path at dc from the shunt inductor base of the transistor to ground, and hence suppresses this effect. VII. MEASUREMENTS The circuit was contacted with Pico G-S-G RF probes for measurements. The noise figure was measured using an Agilent N8975A noise figure analyzer. A summary of the measurement results is shown in Table I. Fig. 19 shows the measured insertion gain versus the simulated gain. The measured gain has a peak of 21 dB from 3 to 8 GHz and rolls of by 4 dB at 10 GHz. We believe that the small departure from simulations is due to inaccuracy in the high-frequency modeling of the interconnects. Fig. 19. Measured and simulated amplifier gain versus frequency. Fig. 20. Measured and simulated noise figure versus frequency. Fig. 20 shows both the measured and simulated noise figure. The measured noise figure agrees well with simulations with a minimum of 2.5 dB from 3 to 6 GHz and rising to 4.2 dB at 10 GHz. Input impedance matching is characterized in Fig. 21, . The measured which shows the measured and simulated is also close to simulations and is below 10 dB from 2.2 to 8 GHz, worsening only slightly to 9 dB at 10 GHz. Fig. 22 shows the input-referred IP3 of the amplifier while swept versus frequency. As expected, the linearity improves as the frequency goes higher. Fig. 23 shows both the in-band and out-of-band compression points while swept versus frequency. Cross-band compression is measured by sweeping the blocking tone with 2276 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 39, NO. 12, DECEMBER 2004 TABLE II COMPARISON WITH THE STATE-OF-THE-ART REPORTED WIDEBAND AMPLIFIERS Fig. 21. Measured and simulated S versus frequency. with a conventional wideband amplifier based on resistor feedback. A systematic methodology was presented to optimize the performance of the wideband LNA. The concept is validated through the measurement results of an SiGe wideband amplifier that achieves a superior performance with moderate power consumption. REFERENCES Fig. 22. Measured IIP3 versus frequency. Fig. 23. Measured in-band and out-of-band CP versus frequency. frequency while keeping the weak signal at 3.4 GHz. As expected, both in-band and out-of-band CPs increase at higher frequencies. At 3.4 GHz, the cross-band CP, which is a two-tone test, is around 3 dB less than the in-band compression, which is a one-tone test as predicted by theory [19]. A summary of the rest of the measurements is also included in Table I. Table II compares the performance of the amplifier with the reported state-of-the-art amplifiers. VIII. CONCLUSION A new method that exploits the unique properties of ladder filters was used to transform the well-known single-frequency reactive matching circuit used in a low-noise tuned amplifier into a wideband matching circuit. A higher gain and lower noise is obtained over a wide frequency range than is possible [1] S. Roy, J. R. Foerster, V. S. Somayazulu, and D. G. Leeper, “Ultrawideband radio design: the promise of high-speed, short-range wireless connectivity,” Proc. IEEE, vol. 92, pp. 295–311, Feb. 2004. [2] R. A. Scholtz, R. Weaver, E. Homier, J. Lee, P. Hilmes, A. Taha, and R. Wilson, “UWB radio deployment challenges,” in Proc. IEEE Int. Symp. Personal Indoor and Mobile Communications, vol. 1, Sept. 2000, pp. 620–625. [3] M. Hamalainen, V. Hovinen, R. Tesi, J. Iinatti, and M. Latva-Aho, “On the UWB system coexistence with GSM900, UMTS/WCDMA, and GPS,” IEEE J. Select. Areas Commun., vol. 20, pp. 1712–1721, Dec. 2002. [4] A. Bellomo, “Gain and noise considerations in RF feedback amplifier,” IEEE J. Solid-State Circuits, vol. SSC-3, pp. 290–294, Sept. 1968. [5] P. Ye, B. Agarwal, M. Reddy, L. Li, J. Cheng, P. Mudge, E. McArthy, and S. Lloyd, “High performance circuits in 0.18 m SiGe BICMOS process for wireless applications,” in Proc. IEEE RFIC Symp., June 2002, pp. 329–332. [6] R. G. Meyer and W. D. Mack, “A 1-GHz BiCMOS RF front-end IC,” IEEE J. Solid-State Circuits, vol. 29, pp. 350–355, Mar. 1994. [7] A. Rofougaran, G. Chang, J. Rael, J. Chang, M. Rofougaran, P. Chang, M. Djafari, J. Min, E. Roth, A. Abidi, and H. Samueli, “A single-chip 900-MHz spread-spectrum wireless transceiver in 1-m CMOS. II: Receiver design,” IEEE J. Solid-State Circuits, vol. 33, pp. 535–547, Apr. 1998. [8] A. N. Karanicolas, “A 2.7 V 900 MHz CMOS LNA and mixer,” in Int. Solid-State Circuits Conf. Tech. Dig., Feb. 1996, pp. 50–51. [9] J. Ryynanen, K. Kivekas, J. Jussila, A. Parssinen, and K. Halonen, “A dual-band RF front-end for WCDMA and GSM applications,” IEEE J. Solid-State Circuits, vol. 36, pp. 1198–1204, Aug. 2001. [10] H. J. Orchard and D. F. Sheahan, “Inductorless bandpass filters,” IEEE J. Solid-State Circuits, vol. SSC-5, pp. 108–118, June 1970. [11] A. Ismail and A. Abidi, “A 3–10 GHz LNA with wideband LC ladder matching network,” in Int. Solid-State Circuits Conf. Tech. Dig., Feb. 2004, pp. 384–385. [12] D. K. Shaeffer and T. H. Lee, “A 1.5-V, 1.5-GHz CMOS low noise amplifier,” IEEE J. Solid-State Circuits, vol. 32, pp. 745–759, May 1997. [13] J. Janssens, J. Crols, and M. Steyaert, “A 10 mW inductorless, broadband CMOS low noise amplifier for 900 MHz wireless communications,” in Proc. IEEE Custom Integrated Circuits Conf., May 1998, pp. 75–78. [14] F. Behbahani, J. C. Leete, Y. Kishigami, A. Roithmeier, K. Hoshino, and A. A. Abidi, “A 2.4-GHz low-IF receiver for wideband WLAN in 0.6 m CMOS architecture and front-end,” IEEE J. Solid-State Circuits, vol. 35, pp. 1908–1916, Dec. 2000. ISMAIL AND ABIDI: A 3–10-GHz LNA WITH WIDEBAND LC–LADDER MATCHING NETWORK [15] B. Agarwal et al., “Broadband feedback amplifier with AlInAs/GasInAs transfer substrate HBT,” Electron. Lett., vol. 34, pp. 1357–1358, June 1998. [16] A. Bevilacqua and A. Niknejad, “An ultra-wideband CMOS LNA for 3.1 to 10.6 GHz wireless receivers,” in Int. Solid-State Circuits Conf. Tech. Dig., Feb. 2004, pp. 382–383. [17] R.-C. Liu, C.-S. Lin, K.-L. Deng, and H. Wang, “A 0.5–14-GHz 10.6-dB CMOS cascode distributed amplifier,” in Proc. Symp. VLSI Circuits, Kyoto, Japan, 2003, pp. 139–140. [18] R. G. Meyer and A. K. Wong, “Blocking and desensitization in RF amplifiers,” IEEE J. Solid-State Circuits, vol. 30, pp. 944–946, Aug. 1995. [19] H. Hashemi and A. Hajimiri, “Concurrent multi-band low-noise amplifiers—theory, design, and applications,” IEEE Trans. Microwave Theory Tech., pp. 290–294, Sept. 1968. [20] H. Knapp, D. Zoschg, T. Meister, K. Aufinger, S. Boguth, and L. Treitinger, “15 GHz wideband amplifier with 2.8-dB noise figure in SiGe bipolar technology,” in IEEE Microwave Symp. (MTT-S) Dig., Phoenix, AZ, 2001, pp. 591–594. [21] A. van der Ziel, “Noise in solid-state devices and lasers,” Proc. IEEE, vol. 58, pp. 1178–1206, Aug. 1970. [22] A. Abidi, G. Pottie, and W. Kaiser, “Power-conscious design of wireless circuits and systems,” Proc. IEEE, vol. 88, pp. 1528–1545, Oct. 2000. [23] H. F. Pues and A. R. Van De Capelle, “An impedance matching technique for increasing the bandwidth of microstrip antennas,” IEEE Trans. Antennas Propagat., vol. 37, pp. 1345–1355, 1989. [24] D. J. Cassan and J. R. Long, “A 1-V transformer-feedback low-noise amplifier for 5–6 GHz wireless LAN in 0.18 m CMOS,” IEEE J. SolidState Circuits, vol. 38, pp. 427–435, Mar. 2003. [25] Y.-K. Chu, C.-H. Liao, and H.-R. Chuang, “5.7 GHz 0.18 m CMOS gain-controlled LNA and mixer for 802.11a WLAN applications,” in Proc. IEEE RFIC Symp., June 2003, pp. 221–224. [26] H. M. Bode, Network Analysis and Feedback Amplifier Design. New York: D. Van Nostrand, 1945, p. 281. [27] R. M. Fano, “Theoretical limitations on the broadband matching of arbitrary impedances,” J. Franklin Inst., vol. 249, pp. 57–83, Jan.–Feb. 1950. [28] H. J. Orchard, “Loss sensitivities in singly and doubly terminated filters,” IEEE Trans. Circuits Syst., vol. CAS-26, pp. 293–297, May 1979. [29] M. E. Valkenburg, Analog Filter Design. New York: Holt, Rinehart and Winston, 1982. [30] A. Abidi, “General relations between IP2, IP3, and offsets in differential circuits and the effect of feedback,” IEEE Trans. Microwave Theory Tech., vol. 51, pp. 1610–1612, May 2003. [31] A. van der Ziel, Noise in Solid State Devices and Circuits. New York: Wiley, 1986. , “Gate noise in field effect transistors at moderately high frequen[32] cies,” Proc. IEEE, pp. 461–467, Mar. 1963. [33] , Noise. Englewood Cliffs, NJ: Prentice-Hall, 1954. [34] A. Abidi, “High-frequency noise measurement on FETs with small dimensions,” IEEE Trans. Electron Devices, vol. ED-33, pp. 1801–1805, Nov. 1986. [35] A. Schmidt and S. Catala, “A universal dual band LNA implementation in SiGe technology for wireless applications,” IEEE J. Solid-State Circuits, vol. 36, pp. 1127–1132, July 2001. [36] V. Aparin, E. Zeisel, and P. Gazzeero, “Highly linear BICMOS LNA and mixer for cellular CDMA/AMPS applications,” in Proc. IEEE RFIC Symp., June 2002, pp. 129–132. 2277 [37] F. Bruccoleri, E. A. M. Klumperink, and B. Nauta, “Noice cancellation in CMOS LNAs,” in Int. Solid-State Circuits Conf. Tech. Dig., Feb. 2002, pp. 406–407. Aly Ismail received the B.Sc. (with honors) degree and the M.S. degree in electrical engineering from Cairo University, Giza, Egypt, in 1998 and 2000, respectively. He is currently working toward the Ph.D. degree in electrical engineering at the University of California, Los Angeles (UCLA). He joined the Integrated Circuits and Systems Laboratory, UCLA, as a Research Assistant in 2000. In 2002, he joined Conexant systems, Newport Beach, CA, where he worked on designing RF integrated circuits for cellular systems. He is currently with Skyworks Solutions, Irvine, CA. His research interests include RF integrated circuit and analog/mixed signal circuit design. Mr. Ismail received the Analog Devices Inc. (ADI) Outstanding Student Designer Award in 2003. Asad A. Abidi (S’75–M’80–SM’95–F’96) received the B.Sc. (with honors) degree from Imperial College, London, U.K., in 1976, and the M.S. and Ph.D. degrees in electrical engineering from the University of California, Berkeley, in 1978 and 1981, respectively. He was at Bell Laboratories, Murray Hill, NJ, from 1981 to 1984 as a Member of Technical Staff in the Advanced LSI Development Laboratory. Since 1985, he has been with the Electrical Engineering Department, University of California, Los Angeles (UCLA), where he is a Professor. He was a Visiting Faculty Researcher at Hewlett Packard Laboratories in 1989. His research interests are in CMOS RF design, data high-speed analog integrated circuit design, conversion, and other techniques of analog signal processing. Dr. Abidi was the Program Secretary for the International Solid-State Circuits Conference from 1984 to 1990, and General Chairman of the Symposium on VLSI Circuits in 1992. He was Secretary of the IEEE Solid-State Circuits Council from 1990 to 1991. From 1992 to 1995, he was Editor of the IEEE JOURNAL OF SOLID-STATE CIRCUITS. He has received an IEEE Millennium Medal and the 1988 TRW Award for Innovative Teaching and the 1997 IEEE Donald G. Fink Award. He was a corecipient of the Best Paper Award at the 1995 European Solid-State Circuits Conference, the Jack Kilby Best Student Paper Award at the 1996 International Solid-State Circuits Conference (ISSCC), the Jack Raper Award for Outstanding Technology Directions Paper at the 1997 ISSCC, and the Design Contest Award at the 1998 Design Automation Conference, and received an Honorable Mention at the 2000 Design Automation Conference.