A method to obtain the isothermal static DC curves of microwave FET power amplifiers

Abstract

30 wavelength converters to reach PLR ϭ 10 Ϫ5 . In the MOPS with F ϭ 2 or F ϭ 4, the number of wavelength converters can be reduced to 22 and 16, respectively. Figure 4 demonstrates the performance gain of the MOPS when the switch is equipped with shared FDLs. Comparisons are made between the single-fiber switch and the MOPS where F ϭ 4. We see that the performance is significantly improved or, equivalently, the number of FDLs required to achieve the same performance is reduced. For example, when a ϭ 0.3, the MOPS with four FDLs performs nearly the same as the single-fiber switch with 16 FDLs. Moreover, the MOPS with 16 FDLs outperforms single-fiber switch with full wavelength conversion in most cases. CONCLUSIONIn this paper, we have proposed the MOPS scheme and studied its improved performance in comparison to the traditional single-fiber switch. It has been demonstrated that although the MOPS with no additional contention resolution components cannot easily perform as well as a switch with full wavelength conversion, however, the MOPS significantly reduces the number of wavelength converters and/or FDLs in switches with shared wavelength conversion and/or shared optical buffering configurations, while achieving a lower packet-loss rate.ABSTRACT: This paper proposes a method to obtain the isothermal static DC curves of microwave FET power amplifiers, avoiding the use of pulsed measurements and accounting for the self-heating problem in this type of device. The method requires the determination of the thermal resistance of the device under test and the measurement of its static DC curves under different ambient temperatures.ABSTRACT: A wideband microstrip patch antenna with tilted L-probe is proposed and studied. Given a tilted L-shaped probe and substrate height of about 16.8% of the wavelength, a bandwidth of 37.1% is obtained in the design, and the in-band S 11 parameter is improved. The radiation pattern is stable across the band and an average gain of 7.93 dBi is achieved.