In most cases, a bandpass filter characteristic

is obtained by using a lowpass-to-bandpass frequency

transformation on a known lowpass transfer function. This

frequency transformation controls the location of passband

edges and transfer zero frequencies completely. Using the

“Vlach-Chebyshev approximation” [1] however, we are

able to specify the (Chebyshev) passband limits directly,

together with a free choice of transfer zero locations in the

stopband. In this way it is possible to design bandpass

transfer functions that cannot be obtained from lowpass

functions by a frequency transformation. We think this

method to be the only (and not very well known) analytical

method to obtain such bandpass characteristics. We show

how we designed wave digital realizations from the specification,

through a VHDL descr iption and synthesis into a

Xilinx FPGA (Virtex-II).