Multilayer-integration of wideband LTCC image rejection mixers at K-band

This article presents integration techniques for realizing hybrid K-band image rejection mixer (IRM) modules in low temperature cofired ceramic substrates. The required couplers are integrated together with a pair of mixers in one single ceramic package, making extensive use of the multilayer capabilities of the host substrate. The module operates in a frequency range from 18 - 32 GHz with acceptable conversion loss, yielding an image rejection of more than 14 dB in a band from 18.5 to 25.5 GHz.