Helsinki University of Technology,
Institute of Radio Communications,
Electronic Circuit Design Laboratory,
Otakaari 5 A, FIN-02150 Espoo
The rapid increase in millimetre wave application has resulted in the need for efficient, stable and small-size frequency sources that are low cost and suitable for mass production. In different applications the short and long term frequency stability requirements as well as signal source frequency tuning range and linearity needs may vary quite significantly, therefore the utilisation of monolithic frequency multipliers provides a flexible solution. We have designed and tested monolithic 40 GHz and 20 GHz frequency doublers on three different European foundries using microstrip, coplanar waveguide and lumped component circuits. Active devices employed included enhancement and depletion mode HEMT's and MESFETs. The design was carried out by using both linear and nonlinear simulations and employing different large-signal models for the transistors. The on-chip measured output power at 40 GHz is +2 dBm and the conversion loss 5 dB which result shows the suitability of monolithic frequency doublers for signal generation at millimetre wave frequencies.