Microwave Laboratory
The Lab – Volt Microwave
Technology
Dr. Ahmed Samir
Basic Components
1- The Lab – Volt Gunn Oscillator
2- The Lab – Volt Gunn Oscillator Power Supply
3 – The Lab – Volt Variable Attenuator
4 – The Lab – Volt Thermistor Mount
5 - The Lab – Volt Data Acquisition Interface
6 – Assembly of Components
7 – Waveguide Support
1- The Lab – Volt Gunn Oscillator
[Model 9510]
The source of microwave signal,
generates microwave having frequency
10.525 GHz
2- The Lab – Volt Gunn Oscillator Power Supply
[Model 9501]
The Voltage Control Knob of G.O.P.S allows
you to vary the o/p power of G.O Signal
Note : The frequency is fixed 10.525 GHZ
3 – The Lab – Volt Variable Attenuator
[Model 9532]
To reduce the power level of microwave
signal by the attenuator’s micrometer
4 – The Lab – Volt Thermistor Mount
[Model 9521]
Resistive Element , T (increase) R (decrease)
used to measure the power of microwave signal
propagating through waveguide
5 - The Lab – Volt Data Acquisition
Interface
6 – Assembly of Components
7 – Waveguide Support
Exercise # 1
Exercise Objectives :
• How to measure the power of the Gunn
Oscillator signal .
• Observe the effect of Thermistor Mount .
• Observe the power Variabition by Variable
Attenuator .
• How to use Power Meter of LVDAM-MW .
Procedure
•
•
•
•
All power Switches in the off position .
Unscrew the matching screws in thermistor
mount .
Thermistor mount must be connect to the
analog input (DCI) .
G.O.P.S Settings :
Voltage
min
Mode
DC
Meter scale
10v
Continue
• Turn on G.O.P.S and D.A.I .
• Set Gunn Oscillator supply voltage to 8.5v.
• Note that 8.5v is the optimum voltage point of
operation of the oscillator .
• Wait five minutes to warm up .
• Start LVDAM-MW Software :
make sure Stand-alone box is unchecked
and click ok
Continue
• LVDAM-MW Settings :
Gunn Oscillator/VCO Power
ON
Function input 4
Power meter
Gain input 4
0 dB
• Set variable attenuator to the maximum
To do this, turn the attenuator to 10mm C.W.
• Start power meter at mw readings .
• Enter power factor (n) thermistor mount’s
waveguide n= 0.9 [power factor default setting = 1]
• Zero adjust the power meter .
Continue
• Decrease the attenuation by turning screw .
• During this observe that power meter reading
increases & horizontal bar indicator of the
meter fills with green as the reading increases.
• Set variable attenuator to 1.5 mm
• Record the power meter = --------mw.