300-GHz InP HBT Oscillators Based on Common-Base Cross-Coupled Topology

Abstract

Two fundamental-mode oscillators operating around 300 GHz, a fixed-frequency oscillator and a voltage-controlled oscillator (VCO), have been developed in this work based on a 250-nm InP heterojunction bipolar transistor (HBT) technology. Both oscillators adopted the common-base configuration for the cross-coupled oscillator core, providing higher oscillation frequency compared to the conventional common-emitter cross-coupled topology. The fabricated fixed-frequency oscillator and the VCO exhibited oscillation frequency of 305.8 GHz and 298.1-316.1 GHz (18-GHz tuning range) at dc power dissipation of 87.4 and 88.1 mW, respectively. The phase noise of the fixed-frequency oscillator was measured to be dBc/Hz at 10 MHz offset. The peak output power of 5.3 dBm (3.8% dc-to-RF efficiency) and 4.7 dBm (3.2% dc-to-RF efficiency) were respectively achieved for the two oscillators, which are the highest reported power for a transistor-based single oscillator beyond 200 GHz. Index Terms-Frequency control, heterojunction bipolar transistors (HBT), voltage-controlled oscillators (VCO). 0018-9480

Measurements of temperature characteristics and estimation of terahertz negative differential conductance in resonant-tunneling-diode oscillators

“…[4][5][6][7] Operating frequency of oscillators with electron devices has also been rapidly increasing from the millimeter wave side. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Among the electron devices, resonant tunneling diodes (RTDs) have been considered as one of the candidates for compact THz oscillators at room temperature. [16][17][18][19][20][21][22][23] Oscillations up to 1.98 THz 23 and relatively high output power in the sub-THz region 24 have been reported for these oscillators.…”

A 310–340-GHz Coupled-Line Voltage-Controlled Oscillator Based on 0.25-$\mu$m InP HBT Technology

“…The oscillator was characterized with two measurement setups [7]. First, the oscillation frequency and the phase noise were measured with a spectrum analyzer for the output signal down-converted with an -band subharmonic mixer.…”

“…The primary requirement for the high-frequency oscillators is the high output power, and III-V technologies have been favored for this aspect. The recent THz oscillators based on III-V technologies are either based on Colpitts [6] or common-base cross-coupling topology [7]. In this work, we propose a new coupled-line structure based on the common-emitter cross-coupled topology, in which the dc blocking capacitors in the coupling path and the load inductance are replaced by a pair of coupled lines.…”

“…For example, for the technology used in this work, a MIM capacitor of 100 fF involves a series inductance of 6 pH, which is comparable to or even larger than the line inductance from the feedback path. This parasitic inductance degrades the oscillation frequency of the cross-coupled oscillator, as indicated by the relation [7] (1)…”

A 269‐278 GHz voltage‐controlled oscillator with uniform output power of 5 dBm

“…The first VCO showed varying output powers of −6 to −1 dBm in the frequency range of 310‐320 GHz . The second VCO increased the output powers to −0.9 to 4.8 dBm over the frequency range of 298‐316 GHz by using larger DHBT devices in cross‐coupled configuration . Both of the aforementioned VCO designs suffer from sizeable power variations across the tunable frequency range.…”