GaAs FET/ UNCOOLE uuz 05 COOLED PARAMETRIC 0.1 FREQUENCY(GHz) IGURE 43.2 Comparison of noise performance of various solid state amplifiers; the InP HEMT compatible with MMIC technology, is a clear choice for receiver applications where cryogenic cooling is D. Willems and I. Bahl, Advances in Monolithic Microwave and Millimeter Wave Integrated Circuits and Systems Symp. Digest, PP. 783-786.@ 1992 IEEE. With permission. In the high-efficiency area, a C-band MMIC amplifier with 70%Pae, 8-dB gain, and 1.7-w power output has een demonstrated. For broadband amplifiers having an octave or more bandwidth, MMIC technology has been exclusively used and is quite promising. Figure 43.5 depicts power performance for single-chip MMIC amplifiers spanning microwave and millimeter wave frequencies. The state of the art in high efficiency and broadband power MMIC amplifiers is summarized in Tables 43. 2 and 43.3, respectively. Note that the high efficiency examples included in Table 43. 2 all exceed 40% PAE. 43.3 Oscillators Solid state oscillators represent the basic microwave energy source and have the advantages of light weight and small size compared with microwave tubes. As shown in Fig. 43.6, a typical microwave oscillator consists of a MESFET as an active device(a diode can also be used)and a passive frequency-determining resonant element, such as a microstrip, surface acoustic wave(SAW), cavity resonator, or dielectric I for fixed tuned oscillators and a varactor or a yttrium iron garnet(YIG) sphere for tunable oscillators. These oscillators have the capability of temperature stabilization and phase locking. Dielectric resonator oscillators provide stable operation from I to 100 GHz as fixed frequency sources. In addition to their good frequency stability, they are simple in design, have high efficiency, and are compatible with MMIC technology. Gunn and IMPATT oscillator rovide higher power levels and cover microwave and millimeter wave bands. The transistor oscillators using IESFETs, HEMTS, and HBTs provide highly cost-effective, miniature, reliable, and low-noise sources for use up to the millimeter wave frequency range, while BJT oscillators reach only 20 GHz. Compared to a gaAs MESFET oScillator, a BT or a HBT oscillator typically has 6 to 10 dB lower phase noise very close to the carrier. Figure 43.7 shows the performance of various solid state oscillators. Higher power levels for oscillators are obtained by connecting high-power amplifiers at the output of medium-power oscillators 43.4 Multipliers Microwave frequency multipliers are used to generate microwave power at levels above those obtainable with fundamental frequency oscillators. Several different nonlinear phenomena can be used to achieve frequenc c2000 by CRC Press LLC© 2000 by CRC Press LLC In the high- efficiency area, a C-band MMIC amplifier with 70% PAE, 8-dB gain, and 1.7-W power output has been demonstrated. For broadband amplifiers having an octave or more bandwidth, MMIC technology has been exclusively used and is quite promising. Figure 43.5 depicts power performance for single-chip MMIC amplifiers spanning microwave and millimeter wave frequencies. The state of the art in high efficiency and broadband power MMIC amplifiers is summarized in Tables 43.2 and 43.3, respectively. Note that the high￾efficiency examples included in Table 43.2 all exceed 40% PAE. 43.3 Oscillators Solid state oscillators represent the basic microwave energy source and have the advantages of light weight and small size compared with microwave tubes. As shown in Fig. 43.6, a typical microwave oscillator consists of a MESFET as an active device (a diode can also be used) and a passive frequency-determining resonant element, such as a microstrip, surface acoustic wave (SAW), cavity resonator, or dielectric resonator for fixed tuned oscillators and a varactor or a yttrium iron garnet (YIG) sphere for tunable oscillators. These oscillators have the capability of temperature stabilization and phase locking. Dielectric resonator oscillators provide stable operation from 1 to 100 GHz as fixed frequency sources. In addition to their good frequency stability, they are simple in design, have high efficiency, and are compatible with MMIC technology. Gunn and IMPATT oscillators provide higher power levels and cover microwave and millimeter wave bands. The transistor oscillators using MESFETs, HEMTS, and HBTs provide highly cost-effective, miniature, reliable, and low-noise sources for use up to the millimeter wave frequency range, while BJT oscillators reach only 20 GHz. Compared to a GaAs MESFET oscillator, a BJT or a HBT oscillator typically has 6 to 10 dB lower phase noise very close to the carrier. Figure 43.7 shows the performance of various solid state oscillators. Higher power levels for oscillators are obtained by connecting high-power amplifiers at the output of medium-power oscillators. 43.4 Multipliers Microwave frequency multipliers are used to generate microwave power at levels above those obtainable with fundamental frequency oscillators. Several different nonlinear phenomena can be used to achieve frequency FIGURE 43.2 Comparison of noise performance of various solid state amplifiers; the InP HEMT LNA, which is also compatible with MMIC technology, is a clear choice for receiver applications where cryogenic cooling is precluded. (Source: D. Willems and I. Bahl, “Advances in Monolithic Microwave and Millimeter Wave Integrated Circuits,” IEEE Int. Circuits and Systems Symp. Digest, pp. 783–786. © 1992 IEEE. With permission.)