DISTRIBUTED OSCILLATOR FOR GENERATING A HIGH FUNDAMENTAL FREQUENCY MICROWAVE SIGNAL HAVING HIGH POWER OUTPUT

摘要

Distributed oscillator for generating a high frequency microwave signal. The oscillator (I) comprises a plurality of gain cells (2, 3, 4) in a parallel configuration. Each of the gain cells comprises a bottom n-MOSFET (metal oxide semiconductor field effect transistor) (5) and a top n-MOSFET (metal oxide semiconductor field effect transistor) (6) each having a gate length of 0.18pm. The drain (7) of each bottom n-MOSFET is coupled to the gate (8) of each top n-MOSFET through a coplanar waveguide (CPW) (9). The drain (10) of each top n-MOSFET is connected to a drain transmission line (10a) and the gate (II) of each bottom n-MOSFET is connected to a gate transmission line (11a). The drain transmission line comprises a coplanar waveguide (CPW) (12a) at each end thereof and a coplanar waveguide (CPW) (3a) between every two drains and the gate transmission line comprises a coplanar waveguide (CPW) (14a) at each end thereof and a coplanar waveguide (CPW) (15a) between every two gates. The output end of the drain transmission line is connected to the input end of the gate transmission line through a feed back path (16). The body (17) and source (18) of each bottom n-MOSFET and each top n-MOSFET are earthed. The input end of the drain transmission line is connected to a voltage supply (19). The output end of the gate transmission line is connected to a frequency collector (20) and the gates of the top n-MOSFETs each is connected to a voltage supply (21a, 21b, 21c). The length of each of the end CPWs in the drain transmission line and gate transmission line is half the length of the CPW between every two drains or gates and the length of each CPW coupling the gate of a top n-MOSFET and drain of a corresponding bottom n-MOSFET is greater than the length of the CPW between every two drains or every two gates by a factor of at least 3. (Fig 1)