An X/Ku Dual-Band Switchless Frequency Reconfigurable GaAs Power Amplifier

Abstract

This letter presents an <inline-formula> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula>/ <i>Ku</i> dual-band switchless power amplifier (PA) with frequency reconfigurable operation in a 0.25-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> GaAs pHEMT process. The proposed reconfigurable PA consists of one dual-band drive amplifier and two single-band amplifiers in parallel. The first stage drive amplifier works in dual-band mode of <inline-formula> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula>-band and <i>Ku</i>-band, and the two single-band amplifiers work in <inline-formula> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula>-band and <i>Ku</i>-band, respectively. An interstage coupled line is used to split the dual-band frequencies into high-band (<i>Ku</i>-band) and low-band (<inline-formula> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula>-band), and the output-stage coupled line acts as a combiner. The operating frequency band of the proposed PA can be changed by turning off drain voltages of unused single-band amplifiers. Measurements results show that the proposed reconfigurable PA features a maximum power-added efficiency (PAE) of 44.4&#x0025; and a power gain of 19.6 dB while delivering an output power of 29.6 dBm at 8.5&#x2013;9.5 GHz of the low-band mode. At 15.5&#x2013;16.5 GHz of the high-band mode, the PA achieves a maximum PAE of 38.4&#x0025;, a power gain of 18.1 dB with an output power of 30.1 dBm. The chip area of the proposed reconfigurable PA is 2 <inline-formula> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 2 mm² including all RF and dc pads.