Model SX-14000 Experiments

Study of reflex Klystron tube

Frequency and guide wavelength Measurement

VSWR Measurement

Impedance Measurement

Model SX-14001 Experiments

Study of Gunn oscillator

Frequency and guide wavelength Measurement

VSWR Measurement

Impedance Measurement Model SX-14002 (Waveguide Antenna Trainer Kit) Experiments

• Measurement of gain and radiation pattern of E -sectorial Horn
• Measurement of gain and radiation pattern of H -sectorial Horn
• Measurement of gain and radiation pattern of Pyramidal Horn
• Measurement of gain and radiation pattern of Parabolic Disc Horn
• Measurement of gain and radiation pattern of Dielectric Antenna
• Measurement of gain and radiation pattern of Slotted antenna broad wall
• Measurement of gain and radiation pattern of Slotted antenna narrow wall
• Measurement of gain and radiation pattern of Pick up Horn

Model SX-14003 Experiments

Dielectric constant measurement of solid dielectric material

Dielectric measurement of liquid dielectric material

Measurement of Phases Shift

Measurement of 'Q' of cavity Model SX-14004 Experiments

To study magic tee, directional coupler, isolators & circulators

To measure characteristic of detector diode

To study attenuation measurements

To study the return loss measurements

Scientific Microwave manufactures two type of power supplies for the microwave benches in X-Band.

Klystron Power Supply

For the klystron based microwave bench. Klystron power supply generates required beam and repeller voltage for the X-Band klystron tube like 2K25. It is very stable and contains the short circuit protection circuit. Also it has amplitude and frequency modulation circuits for the generation of 1 KHz square wave and the saw tooth wave.

Specifications

Model SKPS-610

Beam Supply:

• Voltage Range: 200-450 V continuously Variable


• Current: 50mA Max


• Regulation: Better than 0.5% for 10% variation in the mains supply voltage


• Ripple: Less than 5 mV rms


• Repler supply Voltage Range: 10V to 270 V DC Continuously variable with respect to klystron cathode


• Regulation: 0.25% for 10% variation in the mains supply voltage


• Heater Supply: 6.3 V DC (Regulated)

Modulation:

• Square Wave: Max. Amplitude: + 110 V peak to peak Freq.: 500 Hz-2000Hz Amplitude and frequency continuously variable


• Sawtooth: Amplitude: -60 V max. peak to peak Freq.: 50 Hz-150 Hz Amplitude and frequency continuously variable


• Operating Voltage: 230V 10%, 50 Hz, A.C.

Gunn Power Supply:

For Gunn based bench. It is regulated power supply to operate the gunn oscillator. It also contains square wave generator to provide 1KHz frequency to the pin modulator for amplitude modulation.

Specifications:

Voltage Range: 0-12V continuously variable

Current: 1A max

Regulation: 0.2 % for 10 % variation in the mains supply voltage

Ripple: 1mVrms

Modulation frequency: 1kHz +/- 10% (900-1100kHz)

Output Connector: BNC (F) for Gunn Oscillator and TNC (F) for Pin Modulator

It is a high gain, voltage amplifier tuned at the center frequency of 1 KHz It is used for VSWR, attenuation and total mismatch on the line

Specifications:

Model : VSWR-115

• Sensitivity: 0
2ƒÊVat a 200 ohm input impedance for full scale deflection

• Noise level: At least 5 dB below full scale at rated sensitivity and maximum bandwidth with input terminated in 100 ohm and 500 ohm for crystal low and high impedances respectively


• Calibration: Square law, meter indicates SWR in dB
  
• Range: 70 dB, input attenuator provides 60 dB in 10 dB steps, accuracy ± 0
2dB per 10 dB stepsMaximum cumulative error ± 05 dB

• Scale selector: Normal, Expand & -5dB
  
• Meter Scale: SWR1-4, SWR3-10, Expand1-1
3, dB0-10, expand dB0-2

• Gain control: Adjust the reference level, variable range 0-10dB approx


• Input: "Bolo" bias provided for 4
3mA low current bolo meters "Crystal" 200 ohms for low impedance crystal rectifier and 200K ohms high impedance

• Crystal: Rectifier as null detector


• Recorder: Socket provided for
  
• Recording: Having 1 V for full scale deflection, internal resistance of 1000 ohms or less


• A/C Output: BNC connector for amplified output


• Input Connector: BNC(F)
  
• Frequency: 1000Hz ± 10%
  
• Power: 230 volts A
C ± 10%, 50Hz mains supply

A waveguide is a hollow metallic tube of any cross section through which the transmission of the electromagnetic waves takes place by the successive reflections from the inner walls of the tube. The cross section of the waveguide is related to the frequency of the waves and is suitable for the transmission of signal in microwave frequency range. The rectangular waveguide is by far more important from a practical point of view, mainly because of the simplicity of the propagation phenomena involved.

Specification

Waveguide	Band	Freq. Range (GHz)	Inner Cross Section (mm)	Outer Cross Section (mm)
WR-284	S	2.60-3.95	72.14 x 34.04	76.20 x 38.01
WR-229	C	3.95-5.85	58.17 x 29.083	61.42 x 32.33
WR-137	J	5.85-8.20	34.85 x 15.799	38.10 x 19.05
WR-90	X	8.20-12.40	22.860 x 10.160	25.40 x 12.70
WR-62	Ku	12.40-18.00	15.799 x 7.899	17.83 x 9.93
WR-42	K	18.00-26.50	10.688 x 4.318	12.70 x 6.35
WR-28	Ka	26.4-40.1	7.112 x 3.556	9.14 x 5.59

A tunable probe helps in detecting the low frequency square wave modulated microwave signal. It is made by the use of crystal diode mounted in the transmission line. The probe is connected to the crystal detector so that the output from the detector is proportional to the square of the input voltage at the position of the probe. As the position of the probe is moved along the waveguide slot it gives output proportional to the standing wave pattern inside the waveguide.

Waveguide	Band	Freq. Range (GHz)	Waveguide	Crystal detector	Output Connectors
STP-153	S	2.60-3.95	WR-284	IN-21	BNC (F)
CTP-153	C	3.95-5.85	WR-229	IN-21	BNC (F)
JTP-153	J	5.85-8.20	WR-137	IN-23	BNC (F)
XTP-153	X	8.20-12.40	WR-90	IN-23	BNC (F)
KuTP-153	Ku	12.40-18.00	WR-62	IN-23	BNC (F)
KTP-153	K	18.00-26.50	WR-42	IN-23	BNC (F)

Scientific microwave offers frequency meters such as:

Direct Reading Frequency Meter (DRF)

It is constructed from a cylindrical cavity resonator with a variable short circuit termination. The shorting plunger is used to change the resonance frequency of the cavity by changing the cavity length. DRF measures the frequency directly. It is particularly useful when measuring frequency differences of small changes

Specification

Model	Band	Freq. Range (GHz)	Waveguide	Calibration	VSWR
XFM-139	X	8.20-12.40	WR-90	+/-2	1.02
KuFM-139	Ku	12.40-18.00	WR-62	+/-2	1.02
KFM-139	K	18.00-26.50	WR-42	+/-2	1.02

These frequency meters are intended for moderate accuracy application in microwave measurements and are usually best for this purpose. These permit full power flow down the transmission line except at the tuned frequency. It consists of a cavity, plunger and the section of standard waveguide. The plunger ensures precise control of its position enabling frequency measurement with high accuracy.

Specification

Model	Band	Freq. Range (GHz)	Waveguide	Calibration Increment (MHz)	VSWR
SFM-125	S	2.60-3.95	WR-284	10	1.03
CFM-125	C	3.95-5.85	WR-229	10	1.03
JFM-125	J	5.85-8.20	WR-137	10	1.03
XFM-125	X	8.20-12.40	WR-90	10	1.03
KuFM-125	Ku	12.40-18.00	WR-62	10	1.03
KFM-125	K	18.00-26.50	WR-42	10	1.03

through wide range of frequencies. These modulators utilize PIN diode which are mounted across the waveguide line with a R.F. isolated DC bias lead passing to an external TNC (F) connectors.

Model	Bias voltage (Max)	Output Connector	Waveguide
XPM-141	10 volts	TNC (F)	WR-90

This is an economical source of microwave power in which Gunn diode is used which work on negative resistance produced by application of DC bias. Precision micrometer fitted with the plungers is used to change the frequency of the oscillations.

Model	Bias voltage (Max)	Output Connector	Waveguide
XG-130	10 volts	BNC (F)	WR-90

It is a waveguide of suitable length having octal base on the broad wall of the waveguide for mounting the klystron tube. It consists of movable short at one end of the waveguide to direct the microwave energy generated by the klystron tube. A small hole located exactly at the center of the broad wall of the waveguide is used to put the coupling pin of the tube as the electric field vector of EM energy is maximum at the center only. The maximum power transfer can be achieved by tuning of the movable plunger.

Model	Band	Freq. Range (GHz)	Waveguide
SKM-139	S	2.60-3.95	2.60-3.95
CKM-139	C	3.95-5.85	WR-229
JKM-139	J	5.85-8.20	WR-137
XKM-139	X	8.20-12.40	WR-90
KUKM-139	Ku	12.40-18.00	WR-62

This system consists of a transmission line (waveguide), a traveling probe carriage and facility for attaching/detecting instruments. The slot made in the center of the broad face do not radiate for any power of dominant mode. Slotted section is basically used to measure standing wave ratio (VSWR). The precision built probe carriage having centimeters scale with a vernier reading of 0.1 mm least count is used to note the position of the probe. Additionally slotted section can be used to measure impedance, reflection coefficient and the return loss.

Model	Band	Freq. Range (GHz)	Waveguide	VSWR	Slope (dB)
SSS-148	S	2.60-3.95	WR-284	1.02	+/-0.2
CSS-148	C	3.95-5.85	WR-229	1.02	+/-0.2
JSS-148	J	5.85-8.20	WR-137	WR-137	+/-0.2
XSS-148	X	8.20-12.40	WR-90	1.02	+/-0.2
KuSS-148	Ku	12.40-18.00	WR-62	1.02	+/-0.2
KSS-148	K	18.00-26.50	WR-42	1.02	+/-0.2

For perfect matching sometimes it is required that the microwave power in a waveguide be absorbed completely without any reflection and also insensitive to frequency. For this attenuators are used. Attenuators are commonly used for measuring power gain or loss in dBs for providing isolation between instruments, for reducing the power input to a particular stage to prevent overloading. Scientific Microwave offers fixed and variable attenuator-s to its customers.



Variable Attenuators

These attenuators provide continuous attenuation of power upto 20 dB.

Model	Band	Freq. Range (GHz)	Waveguide	Attenuation (dB)	VSWR	Accuracy
SA-101	S	2.60-3.95	WR-284	0-20	1.1	+/-0.5dB
CA-101	C	3.95-5.85	WR-229	0-20	1.1	+/-0.5dB
JA-101	J	5.85-8.20	WR-137	0-20	1.1	+/-0.5dB
XA-101	X	8.20-12.40	WR-90	0-20	1.1	+/-0.5dB
KuA-101	Ku	12.40-18.00	WR-62	0-20	1.1	+/-0.5dB
KA-101	K	18.00-26.50	WR-42	0-20	1.1	+/-0.5dB