| 摘要 |
PROBLEM TO BE SOLVED: To attain multiplexing, to reduce a time side lobe and to avoid the S/N from being deteriorated. SOLUTION: In the spread spectrum communication equipment that uses a chirp signal for spread spectrum processing, a SAW-DDL 4 that receives a multiplexed input RF pulse based on binary differential phase data and transmits a multiplexed binary differential phase modulation chirp signal changed by a phase step of π-radian based on a reference frequency to decide a differential phase amount from a reference interval corresponding to one-bit of the binary differential phase data and is provided with two systems of an input electrode that receives the binary differential phase modulation chirp signal and two output electrode pairs corresponding to the input electrode and connected in cascade in a propagation path of a surface acoustic wave converted by the input electrode. Then a data demodulation SAW matched filter 13 where a center position of the two output electrodes of each system is deviated by λ0 /2 each where λ0 is a propagation wavelength of a surface acoustic wave of a reference frequency is used for a demodulator, and the chirp signal for communication is a chirp signal whose frequency change per unit time changes with time. |
