Millimeter Image Rejection Harmonic Mixer

Mixer is the key component in the millimeter wave (MMW) communications, radar, electromagnetic countermeasure, and measurement systems. Having the property of good image rejection in broadband and low intermediate frequency (IF) cases, the image-rejected mixers (IRM) have been widely used in various MMW receivers. By using IRM, heterodyne receiver with good image rejection and MMW-to-IF once frequency conversion can be realized, which simplified receiver constitution prominently. The number of Local Oscillation (LO) sources is reduces and Electromagnetic Compatibility (EMC) of MMW system is improved. Also, the size, weight, power consume and cost of MMW receiver is reduced.In MMW band, generating LO signal with high quality is difficult and costly. This problem could be resolved by using sub-harmonic mixer (SHM). Instead of using MMW LO, SHM using microwave signal with frequency equals 1/2 or 1/4 of MMW LO frequency, thus the technical difficulty and cost of MMW system is reduced remarkably.At first, the design and implementation of MMW hybrid integrated sub-harmonic image rejection mixer is presented in this paper. The sub-harmonic mixer is used as unit mixer to reduce LO to its 1/4. The image rejection mixer is composed of two unit mixers, RF is halved as two parts in quadrature; LO is halved as two parts in phase; IF is synthesized in quadrature. The amplitude and phase balance of the unit mixer is controlled strictly through designing. Wideband image rejection is realized in the condition of the fixed IF. The mixer is fabricated using HMIC process based on the thin film ceramic substrate and tested. The results showed conversion loss less than 11.2dB and image rejection ratio more than 20dB over 4GHz RF bandwidth, when IF is 70 MHz fixed.Secondly,the MMIC 20-40GHz HMMC-5040 amplifier is used to realize the PHEMT frequency converter. The feasibility of up/down converter using PHEMT sub-harmonic mixing is validated by the experimental results.At last, on the base of PHEMT multiplying, amplifying and gate mixing, the...