InP DHBT Distributed Amplifiers With Up to 235-GHz Bandwidth

Abstract

Three wideband amplifiers in double-heterojunction bipolar transistor technology have been designed and measured. The amplifiers use different types of distributed amplifier (DA) topologies, all based on cascode gain cells. A single-stage DA design achieves 7.5-dB gain and 192-GHz bandwidth and a two-cascaded single-stage DA achieves an average gain of 16 dB with a bandwidth of 235 GHz. The third circuit is a conventional DA with more than 10-dB gain from 70 kHz up to 180 GHz. To the authors' best knowledge, the single-stage DA and the two-cascaded single-stage DA are the widest band amplifiers in any technology reported to date. Furthermore, the conventional DA has a record bandwidth for circuits in conventional DA topology with gain from near dc.

Ultra-broadband common collector-cascode 4-cell distributed amplifier in 250nm InP HBT technology with over 200 GHz bandwidth

“…For bipolar based DAs, the gain stage is typically a simple common emitter (CE) cell, but recent works have utilized cascode cells in order to benefit of their higher bandwidth and high frequency gain compared to their CE counterparts. Multiple cell distributed amplification with bandwidths higher than 220 GHz has been demonstrated recently using cascode cells [2]- [5]. The cascode gain cell solves the serious bandwidth limitation associated with Miller capacitance of the CE, however an important gain limitation still exists in the form of the resistive input impedance of the cascode.…”

Advances in terahertz communications accelerated by photonics

“…GHz developed by UCL with Chalmers University 82 . Also the hybrid/monolithic integration of UTC-PDs with HEMT/HBT amplifiers for emission at 100 GHz seems to demonstrate an interesting potential for future components of the system [83][84][85] .…”

Bandwidth enhancement technique for bipolar single stage distributed amplifier design

“…Section III demonstrates the applicability of this concept through simulation studies based on full circuit models of an Indium Phosphide InP double heterojuntion bipolar transistor (DHBT) and compares the bandwidth and gain performance of the new technique to the technique adopted in the SSDA with the widest reported bandwidth [2]. Section IV concludes the paper.…”

“…This improvement is achieved by separating the inter-electrode capacitance of individual vacuum tubes while adding their transconductance. Since its introduction, the concept has been applied in the design of amplifiers with very broad bandwidth; the highest reported being 235 GHz using a transistor with 350 GHz transition frequency (f T ) [2].…”