A Monolithic Ultrawideband Reconfigurable Dual-Mode Transceiver Front-End Functioning From 0.8 to 18 GHz in GaAs Technology

This article presents a monolithic 0.8- to 18-GHz reconfigurable dual-mode transceiver (TRX) design with direction and conversion functions. In the direction mode, the TRX processes the signals in a frequency range from 0.8 to 5 GHz. In the conversion mode, it up-converts or down-converts the signals at a frequency from 4.5 to 18 GHz. An overlap of 0.5 GHz exists in the two modes, so that the TRX will be flexible in frequencies from 4.5 to 5 GHz. The receiver (RX) deploys a distributed low-noise amplifier (LNA), three driven amplifiers, a down-conversion mixer, a tunable low-pass filter (LPF), a variable gain amplifier (VGA), and two single-pole-double-throw (SPDT) switches. The transmitter (TX) consists of a VGA, an up-conversion mixer, a reconfigurable distributed power amplifier (PA), three driven amplifiers, and two SPDT switches. In the RX, the two modes share the usage of LNA, tunable LPF, and VGA. Similarly, the two modes of TX share the usage of VGA and PA. Moreover, the PA is designed using reconfigurable bias inductors (INDs) to enhance power efficiency, which is also critical for TRXs. The proposed TRX was prototyped using a commercial 0.15-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>m E-mode GaAs pseudomorphic high electron mobility transistor (pHEMT) process. The RX exhibits a gain range of 7.3–41.9 dB, a gain step of 1 dB, tunable instantaneous bandwidth from 1 to 4.2 GHz, and noise figure (NF) of 4–4.4 dB. The TX demonstrates gain ranging from 2.1 to 30.4 dB and output 1-dB compression point (OP1dB) of 18.8 dBm. The chip occupies 79.8 mm2 area including a padframe, which will be useful for multifunctional systems.