270-GHz HBT Oscillator Performanc Packaged in WR-3.4 Standard Waveguide

In this paper, two identical fixed-frequency oscillators for WR-3.4 band (220 – 320 GHz) are fabricated for RF-probe tests and for waveguide packaging. The oscillator is designed without buffer amplifier based on InP 250nm HBT. The first circuit measured with an RF probe oscillated at 255.5 GHz with an output power of -0.6 dBm. For the second circuit fabricated for waveguide mounting, on-chip waveguide transition replaces the RF probe pad. Simulations indicate the transition provide reflected power of less than -10 dB and insertion loss of better than 0.3 dB over WR-3.4 full band. Oscillation frequency of the waveguide oscillator is 266.8 GHz and the output power is -1.4 dBm.