From Radar Systems for Technicians

Introduction

Because of the high power emitted from a radar transmitter, there is a greater potential for failure in this unit than in any other. The radar technician will probably do more repair work on the transmitter, than on all the other units in the system, and a sound foundation knowledge of the transmitter will pay big dividends in system restoration and outage prevention.

The size of this chapter substantially exceeded preliminary planning. Even so, it is limited from what it might have been; the target size of the entire book played a part in this decision.

The fundamentals of common radar-transmitter hardware were addressed in preceding chapters. This chapter will deal in greater detail with several aspects of the pulsed radar transmitter. One topic will be the origin and composition of the emitted energy, a wide spectrum of frequencies. Another subject is the modulator, which will apply a high-Voltage pulse to a third area of interest, the final power amplifier, which may be a magnetron, a klystron power amplifier tube, a traveling-wave-tube (twt), or an amplitron, also called a cross-field amplifier (cfa). There are still other means to transmit the radar burst. A major component in the modulator is the pulse-forming network, an artificial transmission line; considerable discussion of this device will be contained in this chapter.

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Products & Services
Thin Film Sources
Thin film sources consist of magnetrons, evaporation thermal units, ion beams and other sources that produce deposition materials (vapors or ions) in a thin film system.
Microwave Tubes
Microwave tubes are lamps that produce microwaves.
Pulse Transformers
Pulse transformers interface a pulse forming network (PFN) and a load. They match the impedance of the load to the PFN in order to maximize power-transfer efficiency.
Liquid Level Switches
Liquid level switches are used to detect specific liquid levels or interfaces between liquids. These level measurements are indicated via an electrical switching action.
Radar Systems and Products
Radar systems and radar products have synchronized transmitters and receivers that send radio waves and detect their reflections from objects, surfaces or sub-surface structures.

Topics of Interest

Compressed High-Resolution Pulse (CHIRP) Transmitters In recent years, considerable effort has been devoted to systems which provide a low peak power, but which employ a very wide transmitter pulse;...

The Modulator At one time, pulsed radar modulators were so similar, that, once a technician gained a thorough understanding of the modulator in one system, nearly all others were so similar, that his...

The Klystron Power Amplifier The klystron power amplifier is the transmitting tube in most high-power synthesis systems. It is common that references to such systems are as klystron systems, rather...

Overview This chapter discusses pulse shapes, with their influence on spectra, and stability. The wavelengths used vary from millimeters to meters. Initially radar designers were pleased to have all...

6.2 BASICS OF AIRBORNE DOPPLER RADAR 6.2.1 Block Diagrams and Operation Figure 6.2 shows an example block diagram of the transmitter/receiver for a moving target indicator (MTI) or pulse-Doppler (PD)...