Patent ID: 7818359

Claim:
A direct digital synthesizer for transmission and detection, comprising: a transmitting phase accumulator for outputting phase data (P 1 ) with a clock frequency f 1 ; a transmitting waveform LUT for outputting transmitting signal amplitude data (T) in accordance with said phase data (P 1 ); a curtailing device for outputting phase data (P 2 ) with a clock frequency f 2 (<f 1 ) by implementing curtailing process to said phase data (P 1 ) and also outputting additional data (A) for compensating for phase information disappeared with said curtailing process; wherein said additional data (A) is assigned the binary value indicating which phase region said phase data (P 2 ) belongs according to ‘00’=0° to 360°, ‘01’=360° to 720°, ‘10’=−360° to −720°, and ‘11’=−360° to 0° and said additional data (A) is assigned according to 360° times an integer where ‘00’ is integer 0, ‘01’ is integer 2, ‘10’ is integer −2, and ‘11’ is integer −1; an interpolating device for outputting phase data (P 3 ) with a clock frequency f 3 (>f 2 ) by implementing interpolating process in accordance with said phase data (P 2 ) and said additional data (A) outputted from said curtailing device; and a detecting waveform LUT for outputting detecting signal amplitude data (S) in accordance with said phase data (P 3 ) outputted from said interpolating device.