A 23 GHz Baseband HBT Distributed Amplifier for Optical Communication Systems

Abstract

This paper reports on a practical HBT distributed amplifier MMIC suitable for optical receiver applications. The circuit topology is based upon application of a novel technique which allows baseband operation in conjunction with dc bias stabiliastion and does not consume a large amount of chip area. 2x2 umn2 single emitter finger InGaP/GaAs HBTs with fT = 60 GHz and pdc 100 have been employed. Simulation results show a bandwidth extending from neardc to 23 GHz and an S21 gain of 11±1 dB at midband. The amplifier has a transimpedance gain of 45± 1 dBQ and a group delay variation of± 30 ps across the passband. Eye diagram simulations indicate its potentialfor handling data rates of up to 30 Gbit/s when employed as an optical receiver preamplifier.

InP DHBT Single-Stage and Multiplicative Distributed Amplifiers for Ultra- Wideband Amplification

“…This advantage is attributed to the minimal high-frequency attenuative effects from the shorter lengths of transmission lines required in the SSDA. This merit is even more valuable in the design of DAs based on HBTs, as these have a forward biased PN junction between the base and the emitter, resulting in a complex characteristic impedance on the input ATL, as identified in [20], [21] and shown in Fig. 2 [11], [20], [22], [23].…”

Bandwidth enhancement technique for bipolar single stage distributed amplifier design

“…This effectively introduces higher attenuation with each additional stage of the DA, meaning that fewer stages can be realised before the overall gain begins to drop [7], [8]. These considerations make bipolar transistors better suited in SSDAs than in multistage distributed amplifiers.…”