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-Design, simulation and measurement of a reconfigurable CMOS RF tuner that can be utilized in the RF front-end of a software defined radio are presented. 0.13µm high Q CMOS varactors controlled by a 22bit shift register are placed periodically on a low loss Coplanar Waveguide (CPW) transmission line to form a 4-11GHz reconfigurable tuner. The monolithic tuner does not use any MEMS devices to achieve the reconfigurability.

No abstract

-A dual-mode field programmable RF amplifier / mixer is presented. Transistor switches, low loss CPW lines and RF transistors are combined in a 3-stage distributed topology which can operate as either a distributed amplifier or a distributed mixer. Functional reconfigurability is achieved using one bit programming without changing the signal path. The programmable module in its distributed amplifier mode provides a gain of 8dB in a 3-8 GHz bandwidth. When switched to the distributed mixer mode, it shows a measured average conversion gain of 4dB in a 1-16GHz bandwidth. This circuit is fabricated in a standard 130nm CMOS technology and occupies 4 mm×1.2 mm chip area.Index Terms -CPW line, distributed amplifier, distributed mixer, field programmable, RF.

We are reporting a novel carbon nanotube field effect transistor with a poly-Si bottom gate structure. The device has a gate length of 3µm and achieves a unity gain frequency f T of 2.5GHz and a maximum oscillation frequency f max of >5GHz. The high frequency performance of the device is attributed to the ballistic transport of electrons inside the nanotube and is expected to improve by reducing the gate length.Index Terms -nanotechnology, carbon nanotube, field effect transistor, poly-silicon.