Microwave Communication Trainer.
The increasing use of microwaves, in applications ranging from satellite and terrestrial communications to high-speed computing and data transmission, has resulted in a short-fall of appropriately trained engineers and technicians.
Over three quarters of all microwave circuits are now non-waveguide.The swing towards microstrip technology must be reflected in the courses offered at engineering education institutes.
BE; recognizing the urgent need for suitable training equipment, have developed a microstrip trainer which will provide the means to investigate the technology and techniques used in this important subject area.
MS3000 Microstrip Trainer comprises 18 passive circuit components, 2 active circuits and all the leads and connectors required to construct a variety of commonly used configurations, many of which incorporate microwave integrated circuits (MICs).
The instruction manual supplied with MS3000 provides a comprehensive introduction to the subject in a manner which avoids unnecessary mathematical analysis and provides a series of structured practical assignments.
The only items of test equipment required are a digital multimeter and a 0-20V dc power supply. Ms3000 Mircostrip Trainer covers the training requirements for most courses in microwave ngineering at undergraduate level courses.
Features
•    Latest Microwave Technology
•    PIN Diod Modulator
•    2.0-3.8 GHz VCO
•    Gold Plated RF laminate with PTH
•    No costly test equipment required
•    Safe low power output
•    Conveniently packed for inventory control
The complete Microstrip Trainer consists on followings :

PASSIVE COMPONENTS

•    2 Patch antenna
•    1 DC Biasing unit
•    1 Three-port circulator
•    1 Hybrid ring (rat-race) coupler
•    1 Ring resonator
•    1 Band Pass Filter
•    1 Quadrature coupler
•    1 Unmatched load
•    1 Directional coupler
•    1 Wilkinson power divider
•    3 50 ohm loads
•    1 Short-circuit termination
•    1 10dB/5dB attenuator
•    1 Crystal detector
•    1 Low-pass filter
•    1 Matched load

ACTIVE COMPONENTS

•    1 Volate Controlled Oscillator (VCO)
•    1 S-band MMIC amplifier
•    1 PIN Diode Modulator

MISCELLANEOUS

•    8 SMA plug-plug connectors
•    1 BNC -dual Banana Pins
•    1 DB(9)-Circular lead
•    2 4mm Banana leads
•    1 Spanner
•    - VCO and Detector calibration curves
The MS3000 is supplied in a well protected and robust carrying brief case. Most of the components are packaged in bright aluminum enclosures and their interconnection is by standard SMA couplings; providing secure but easily made joints.
The trainer is designed to be used with basic test equipment: a DC power supply and a digital multimeter; in conjunction with the calibration curves supplied with each VCO and detector.
Realistic quantitative results can easily be achieved with this simple set-up; however the quality of construction allows MS3000 to be used with more sophisticated microwave test instruments if these are available.
The Assignment
The manual provides a series of structured and stand alone assignment; using mostly the passive components: Introduction to microstrip, microwave integrated circuit (MIC) technology and microwave measurement techniques. Further assignments encourage the student to build up complete systems incorporating the active circuits.
The individual units of both active and passive components are designer for compatibilty and easy interconnections, thus ensuring that circuits such as a Line-of-Sight Link or simple Frequency Modulated Continuous Wave (FMCW) can be built and tested with minimum difficulty.
The basic principles and techniques of microwave signal processing using microstrip are simply and comprehensively presented, so that the trainer is ideal for use by engineers and technicians working in a variety of different areas of application, including:
•    Satellite communication
•    Radar
•    Surveillance-Security systems
•    Instrumentation
•    Medical electronics
•    Data transmission

The practical work is presented under the following general headings:

•    Power Source and detector action
•    Action of a 3-port circulator
•    Insertion loss measurement on low-pass filter And Band Pass Filter
•    Measurement of return loss, reflection coefficient and VSWR of a filter, microstrip and commercial matched loads
•    Matching investigations: reflection coefficient of unknown resistive load and its matching by 1/4 λg transformer and shunt stub
•    Properties of a power divider and rat-race coupler
•    Measurement of effective dielectric constant and line loss using a ring resonator
•    DC biasing and MMIC amplifier investigations
•    Quadature coupler investigations
•    Microwave radio link and antenna investigations.
A complete workstation is also available comprising the supply and a digital multimeter.
Specification

Patch Antenna

•    Centre frequency: 2.7 ±0.05GHz
•    Grain: 6dBi (typical)
•    Return loss: -17dB
•    Impedance: 50 ohm

Bias network

This components consist of three types of 50 bias lines. Two a.c and one d.c, all utilizing the quarter wavelength transformer.

Three-port circulator

•    insertion loss: 0.4dB (max at 3GHz)
•    Insertion loss: 0.5dB (max 2.5 -2.9GHz)
•    Isolation: 16 - 24dB (full band 2.5 - 2.9GHz)

Hybrid Ring (rat-race) Filter

This is a standard hybrid-ring (or 'rat-race) coupler
•    Center frequency: 2.7 +0.1GHz
•    Insertion loss (at center frequency): -3.2dB
•    Bandwidth: 400MHz
•    Isolation: 25dB (typical)
•    Impedance: 50

Ring Resonator
A loose-coupled resonant ring designed to resonate at a fundamental frequency of approximately 2.7GHz in its n = 2 mode. This component is used to measure the dielectric constant of the printed circuit board.

Low-pass Filter
A 5-section, L-C type microstrip low-pass filter
o    Pass band (nominal): dc - 2.7GHz
o    Stop band: 3dB point at 3GHz (approx) rising to 20dB at 20% above cut-off
o    Impedance: 50 ohm

Matched Load
A quarter wavelength long terminated in a standard, 50 ohm, thick film, chip resistance
o    Center frequency: 2.7GHz
o    Return loss: -20dB
o    Input impedance: 50 ohm

Unmatched Load
Three 50 ohm input lines terminated in unknown resistive loads. One incorporates a /4 transformer with a center frequency = 3GHz, and one uses an open-circuit shunt stub element.
Wilkinson Power Divider
o    Center frequency: 2.7GHz
o    Operating band: 2 - 4GHz
o    Insertion loss: 3.5 ±0.25dB
o    Isolation: 20dB (typical)
o    Tracking: 0.15dB (typical over full band)
o    Impedance: 50 ohm

Voltage Controlled Oscillator
The VCO is supplied with its own calibration curve and amplifier
o    Frequency range: 2.0 - 3.5GHz
o    Tuning voltage range: 1 - 20V
o    Power output: 10dBm (typical into 50 ohm)
o    Modulated output frequency: 1kHz (variable 900-1100Hz)
o    Modulation waveform: Square wave
o    Modulator indicator: 2Hz flashing LED
o    DC supply voltage: 15V fix (fully protected)
o    DC supply current: 50mA (maximum)
o    Supply connectors: 4mm sockets

S-band MMIC Amplifier
o    Gain: +12dB (typical)
o    Compression point: +12dBm (typical)
o    Frequency range: 2 - 4GHz
o    Input impedance: 50 ohm
o    Output impedance: 50 ohm
o    Supply voltage: 15V (fully protected)
o    Supply current: 40mA (typical)
o    Supply connectors: 4mm sockets

Band Pass Filter
o    Pass band : 2.5 - 2.6GHz
o    Band width : 100 MHz
o    Impedance : 50 ohm

Ancillary Equipment
o    Power Supply: 15V dc, 0 - 20V dc variable, 1.5 A, Regulated DC Power Supply PS-3000 is recommended

Power Requirements
o    Power supplies: 15V dc 1.5A
o    VCO tuning voltage: 0 - 20V dc 1.2A
Dimensions & Weight (in protective case)
Width: 430mm (17in), Height: 310mm (12in), Depth: 89mm (3.5in), Weight: 4.5kg (9.92 lbs)