DEVICE FOR ENCODING AT SURFACE ACOUSTIC WAVES FOR PASSIVE TRANSPONDER Russian patent published in 2006 - IPC H03H9/64 

FIELD: radio-location technologies, in particular, engineering of transponders for system of radio-frequency identification of mobile and immobile objects.

SUBSTANCE: device for encoding at surface acoustic waves for passive transponder has piezo-electric substrate and N opposite-pin transformer pairs, positioned at surface of piezo-electric substrate in parallel rows along its width, while each opposite-pin transformer pair consists of one input opposite-pin transformer and one output opposite-pin transformer and is adjusted for specific working f., N input opposite-pin transformers, to which request signal is sent, are positioned along width of substrate in one plane one below another and are connected electrically in parallel between each other, N output opposite-pin transformers, from which response signal is taken, are positioned in steps along width of substrate in basic positions relatively to input opposite-pin transformers and are also connected electrically in parallel to each other, while at least two pairs of opposite-pin transformers have different working frequencies, selected from M various values, alternation of opposite-pin transformer pairs, having different working frequencies, is individual for each surface acoustic waves device and is appropriate for previously selected code combination, each one of N output opposite-pin transformers can be mounted with shift relatively to base position in one of fixed positions, individual for each surface acoustic waves device and appropriate for previously selected code, so that maximal number of code combinations for current device is (M×L)^N, where M - number of working frequencies of device, L - number of fixed positions of output opposite-pin transformers, including base position, N - number of opposite-pin transformer pairs.

EFFECT: increased number of possible code operations without increase of total dimensions of piezo-electric substrate crystal.

3 cl, 4 dwg