Efficient generation of guided millimeter-wave power by photomixing

Abstract

A 70-GHz bandwidth commercial photodiode has been coupled to W-band waveguide and used as a photomixing source from 75 to 170 GHz. Maximum power conversion efficiency of 1.8% was obtained at 75 GHz, where an optical input of +10 dBm yielded a nonsaturated millimeter-wave (mm-wave) power of 7.5 dBm. Optimizing the photomixer backshort tuning at individual frequencies showed that the mm-wave power decreased with frequency to a level of 30 dBm at 170 GHz. Fixed tuning allowed the generation of power across the full waveguide band from 75 to 110 GHz, with a variation within 5 dB across the majority of the band.

Generation of Local Oscillator Signal via Photomixing

“…However, the power output is largely frequency dependent. This particular setup was designed to operate within W-band (75-110 GHz), but the output power is still detectable up to about 625 GHz (Huggard et al 2002a). The power output varies approximately as the inverse fourth power of frequency.…”

“…They have demonstrated previously a 75-170 GHz photomixing source by beating two commercially available 1.55 µm communication lasers using an InGaAsP (Indium-Gallium-ArsenidePhosphide) photodiode. The group has also investigated the possibility of extending the system up to 600 GHz (Huggard et al 2002a, b) and a similar system operating cryogenically at 77 K had also been used as an LO for a linear receiver array (Fontana et al 2007). Figure 9.1a, b show the current system setup and the internal construction of a photomixer block.…”

Photonic mm-wave local oscillator

“…In contrast the contribution of the single laser phase noise to the open loop phase noise of our system is determined by phase noise of the laser times ( τ / τc ) 2 ,where τc is the coherence time of the laser and τ is the path delay of the MZI. The value of ( τ / τc ) 2 is very small for a MZI with a free spectral range of 75 GHz (a delay of 1.3*10 -11 s) and a laser coherence time of 10 -6 s.…”

“…Huggard and B.N. Ellison of Rutherford Appleton Labs [2] in November of 2003. All optical devices and connections are polarization maintaining.…”

Active Millimeter-Wave Radiometry for Nondestructive Testing/Evaluation of Composites—Glass Fiber Reinforced Polymer

“…The photomixer consisted of a high speed InGaAs photodiode coupled to a standard rectangular WR10 waveguide. Although the photomixer is normally used to produce a single W-Band frequency when driven by two lasers [31], in this case the frequency components within the incoherent light from the EDFA beat with each other to generate a wide mm-wave spectrum. This spectrum was characterized as shown in Fig.…”