tailieunhanh - RECEIVER TYPES AND CHARACTERISTICS

Besides the considerations of noise and noise figure, the capabilities of receivers are highly dependant on the type of receiver design. Most receiver designs are trade-offs of several conflicting requirements. | RECEIVER TYPES AND CHARACTERISTICS Besides the considerations of noise and noise figure the capabilities of receivers are highly dependant on the type of receiver design. Most receiver designs are trade-offs of several conflicting requirements. This is especially true of the Electronic Support Measures ESM receivers used in Electronic Warfare. This section consists of a figure and tables that provide a brief comparison of various common ESM receiver types. Figure 1 shows block diagrams of four common ESM receivers. Table 1 is a comparison of major features of receivers. Table 2 shows the receiver types best suited for various types of signals and Tables 3 and 4 compare several direction of arrival DOA and emitter location techniques. Table 5 shows qualitative and quantitative comparisons of receiver characteristics. CRYSTAL VIDEO RECEIVER YIG TUNED NARROWBAND SUPERHET RF AMPLIFIER S BAND 2 VIDEO COMPRESSIVE VIDEO AMPLIFIER r BAND 1 A VIDEO BAND 3 VIDEO WIDEBAND SUPERHET INSTANTANEOUS FREQUENCY MEASUREMENT RECEIVED SIGNAL FREQUENCY INFORMATION LINE Figure 1. Common ESM Receiver Block Diagrams Table 1. Comparison of Major Features of Receivers Receiver Advantages Disadvantages Principal Applications Wideband crystal video Simple inexpensive instantaneous High POI in frequency range No frequency resolution Poor sensitivity and Poor simultaneous signal performance RWR Turned RF Crystal Video Simple Frequency measurement Higher sensitivity than wideband Slow response time Poor POI Option in RWR Frequency measurement in hybrid IFM Relatively simple Frequency resolution Instantaneous high POI Cannot sort simultaneous signals Relatively poor sensitivity Shipboard ESM Jammer power management SIGINT equipment Narrow-band scanning Superhet High sensitivity Good frequency resolution Simultaneous signals don t interfere Slow response time Poor POI Poor against frequency agility SIGINT equipment Air and ship ESM Analysis part of hybrid Wide-band Superhet Better response .