Microwave Resonant Tunneling Diode Oscillator
Integrated Circuits
Name: LINGSHUANG YANG Student ID: 2110784 Supervisor: Edward Wasige
Electrical and Electronic Engineering, University of Glasgow
Introduction
Emitter
Collector
(a)
Figure 2 power combining topology
Oscillator Design
Formulas
Parameters
Self-capacitance (Cn)
25GHz
Resonant inductance (L)
35GHz
45GHz
Stabling resistor (Re)
Decoupling capacitor
(Ce)
 Optical lithography:
transfer computer
pattern to wafer.
Wet
Dry
output power: dBm
 Wet/Dry etching
-10
-20
span= 50 GHz
-30
 Metallization (a)
and lift-off (b)
-40
-50
-60
-70
-80
29
29.5
Results
30
30.5
31
31.5
32
Frequency: GHz
output power: dBm
-10
-20
span= 2.88 GHz
-30
-40
-50
-60
-70
-80
29
29.5
30
30.5
31
31.5
32
Frequency: GHz
Figure 5 I-V characteristic of RTD
figure 6 output power of RTD oscillator
Figure 5 prove that RTD is fabricated successfully, as it has NDR
region, and the output power of oscillator reaches to -9.37 dBm
at 30.75 GHz.
RTD oscillator design and four crucial fabrication processes have
been provide in this poster. From the measurement result, it can
be seen that the power combining technique achieves the output
power of oscillator to milli-watt range.
Reference
20 ohm
25GHz
35GHz
45GHz
Fabrication Processes
Conclusion
Table 1: oscillator parameters design
Components
(c)
Figure 4 RTD oscillator L-edit layout
RTDs and Power Combining Technique
 RTD is a negative differential resistor (current decreases
with the increase of voltage apply on resistor). The damping
ratio of NDR oscillator is less than zero, this results a
continuous increase of amplitude of current in circuit (figure
1). NDR will generate power by contrast with ordinary resistor.
 Operation principle of RTD: figure 2 shows that the electrical
band diagram of double quantum well structure. Ec and EF are
edge of conduction band and the Fermi level respectively, E0
and E1 are resonant tunnelling state. Fig 2 (a) shows that a
bias voltage applied DBQW, increasing bias results the
conduction band shift to lower level.
While the E0 shift to same value of
energy of electron, electron pass
(a)
though the barrier without any
reflection. Thus, the current will
increase sharply. As shown in fig 2
(b), when the E0 shift to lower level,
resonant state will be end. Hence the
current will decrease until it increase
(b)
again, and this region is the NDR
region of RTD.[1]
 Power combining topology combines output power of two single
Figure 1 band diagram[2]
RTD oscillator. This results that a
milli-watt output power can be achieved.
Inherent problem associated
with effectively utilizing the
two-terminal NDR gain to
achieve the output power in
desired range i.e. milli-watt
range is existed.[3]
(b)
63.69pF
45.49 pF
35.38 pF
[1] J. Wang, "Monolithic microwave/millimetrewave integrated circuit resonant tunnelling diode
sources with around a milliwatt output power," PhD thesis, University of Glasgow, 2014
[2]S. Montanari, Fabrication and characterization of planar Gunn diodes for Monolithic Microwave
Integrated Circuits. Forschungszentrum Jülich GmbH, 2005.
[3] A. Ofiare, J. Wang, K. Alharbi, A. Khalid, E. Wasige, and L. Wang, “Novel Tunnel Diode
Oscillator Power Combining Circuit Topology based on Synchronisation,”