The design of BBA filter and IF transceiver for 155 Mbps application wireless ATM

In this paper, it is focus on the group delay of BBA (Base Band Analog) filter and IF transceiver module for wireless ATM (Asynchronous Transfer Mode). In order to improve the group delay, the singly equalized form of BBA filter is adapted. In the case of IF transceiver module, the response characteristic of 3 dB ripple and the IMD characteristic of -50 dBc are measured. The measurement result doesn´t match the specification of IF transceiver (ripple is 1 dB and IMD is -60 dBc), at first, the reason is, however, discussed. Two method will be suggested in order to improve the response characteristic of IF transceiver