A 90-nm CMOS Broadband and Miniature Q-band Balanced Medium Power Amplifier

Abstract

This paper presents a Q-band balanced medium power amplifier fabricated using standard 90-nm 1P9M CMOS technology. The balanced amplifier, which is constructed with two broadband amplifiers and two broadside couplers using thinfilm microstrip (TFMS) line technique, has a compact chip size of 0.78 x 0.92 mm2. The MMIC demonstrates a measured gain of 14.5 dB at 48 GHz. With the feature of the balanced amplifier, the MMIC has a 3-dB bandwidth up to 37.2 % from 35 to 51 GHz with flat gain and return loss frequency response. Furthermore, the balanced amplifier delivers a saturation output power of 10.6 dBm with 8% PAE and OPldB is 7.5 dBm.Index Terms -Millimeter-wave (MMW), Q-band, CMOS, balanced amplifier, thin-film microstrip (TFMS), broad-side coupler.

Advances in Silicon Based Millimeter-Wave Monolithic Integrated Circuits

“…This leads to the significant decrement in output power. In order to achieve higher output power, the transistors can be combined by direct shunt combining 3-dB couplers and transformers [73][74][75][76][77][78][79][80][81]. Direct shunt combining is the simplest combining architecture to combine the current of each PA cell, in turn; the output power is enlarged.…”

A 68–83 GHz power amplifier in 90 nm CMOS

“…1. The balanced amplifier topology is to achieve higher output power and good return loss [2]. The schematic of the PA cell is shown in Fig.…”

“…The 90 o couplers used in this CMOS PA are broadside coupler [2]. Metal 9 and 8 are used to realize the broadside coupler.…”

“…The CMOS PA is one of the most challenging blocks in the RF circuits because of the low voltage and current durability, and the loss in millimeter-wave (MMW) frequency. There have been 60 GHz and 90-100 GHz CMOS PAs reported [2]- [7], but very few in 70-80 GHz frequency range. One 77 GHz PA [1] in CMOS process was reported with 11.8-dBm output power.…”

Recent development of millimeter-wave CMOS monolithic integrated circuits

“…Both of the chips were designed using thin-film microstrip line (TFMS) to avoid the loss from the bulk Si-substrate. Another balanced amplifier in 90-nm CMOS covering 35-51 GHz was also developed [17]. This amplifier combines two identical single-ended cells via a pair of 90 o broadside couplers to achieve better power performance.…”