Novel realisation of an automatic transmit-receive switch and two bandpass filters by a single SAW filter

In the letter we describe and demonstrate a completely new application of SAW filters in present-day communication systems to realise a kind of transmit-receive switch (TRS). The TRS using the SAW filter works well up to expectations, replacing the required two bandpass filters and an antenna directional coupler. To do this the undesired reverse propagation sidelobe (higher) of a group-type unidirectional transducer (GUDT) has been used to advantage. The theoretical and experimental results are found to be in one-to-one correspondence.