Switched-current analog programmable filter for software-defined radio

We have proposed a switched-current (SI) analog programmable finite-impulse-response (FIR) filter for software-defined radio. The programmable tap coefficient circuit for programmable operation of the SI FIR filter has also been proposed. The 4-bit-resolution tap coefficient circuit has been designed and fabricated using 0.35 μm complementary-metal-oxide-semiconductor technology. The current error between measured and calculated tap coefficient circuits has been less than 2%. The radio frequency/intermediate frequency SI band-pass filter has been designed using the measured tap coefficients. The designed SI FIR filter has a frequency response as well as calculated tap coefficients. The maximum operating frequency of the proposed SI FIR filter using 0.13 μm CMOS technology has been estimated to be greater than 10 GHz with circuit simulation.