High-Power 268-GHz Push-Push Transformer-Based Oscillator With Capacitive Degeneration

225 GHz triple‐push RTD oscillator with 0.5 mW dc‐power consumption

“…The frequency region of 200-300 GHz, rather than that above 1 THz, is considered more practical for wireless communication transceiver systems in terms of the width of the THz window, the free-space path loss, and the maturity of the IC design. Table 1 shows a performance comparison with previously published harmonic oscillators operating in a frequency range of 100-340 GHz [7][8][9][10][11][12][13][14][15]. Compared to the push-push RTD oscillator [15], the triple-push RTD oscillator showed 13 dBm higher P OUT and 17.8 times higher dc-to-RF efficiency with a slight increase in P DC .…”

“…Table 1 shows a performance comparison with previously published harmonic oscillators operating in a frequency range of 100–340 GHz [7–15]. Compared to the push–push RTD oscillator [15], the triple‐push RTD oscillator showed 13 dBm higher P OUT and 17.8 times higher dc‐to‐RF efficiency with a slight increase in P DC .…”

“…Compared to the conventional transistor‐based harmonic oscillators [7–14], the triple‐push RTD IC showed an extremely low P DC of sub‐mW levels with good dc‐to‐RF efficiency. These results are due to the RTD characteristics with the low bias voltage of 0.4 V and the low J P of 0.74 mA/μm 2 and the efficient triple‐push topology exploiting the strong odd symmetry of the RTD I – V curve with the wide NDR span of 0.46 V. The transistor transconductance ( g M ) is proportional to the square root of the drain current for metal–oxide–semiconductor (MOS)‐type transistors and proportional to the collector current for bipolar junction transistor (BJT)‐type transistors [31].…”

“…Under conditions where the cut‐off frequency ( f MAX ) of semiconductor devices is limited, a harmonic oscillator topology has been utilised to increase the operating frequency of the IC [7–15]. In the previous work, we verified experimentally that the RTD‐based triple‐push oscillators utilising third harmonics operate above f MAX of RTDs [16].…”

High Power and High Frequency CMOS Oscillator With Source-to-Drain Coupling and Capacitive Load Reduction Circuit

“…As a result, in most of the published work using frequency multipliers, the signal source is generated using an external signal generator that is bulky and expensive in real operations. Second, the harmonic oscillators extract the n th harmonic signal from output port [28][29][30]. At several GHz frequency range, rotary traveling-wave oscillators (RTWOs) that could extract high order harmonic frequencies are widely adopted [31][32][33].…”