Hikita M, Takubo C, Asai K
Central Research Lab., Hitachi Ltd., Kokubunji-shi, Tokyo 185-8601, Japan.
IEEE Trans Ultrason Ferroelectr Freq Control. 2000;47(1):233-41. doi: 10.1109/58.818766.
New surface acoustic wave (SAW) convolver structures with high conversion efficiency and self-temperature compensation characteristics have been developed. Strong piezoelectric substrates, regardless of temperature coefficients of delay (TCD), can be used in these convolvers. New demodulation techniques using the developed SAW convolver for high bit rate and wideband spread spectrum code division multiple access (CDMA) communications have also been developed. I- and Q-channel demodulation data can be derived directly from binary phase shift keying (BPSK) or quadri-phase shift keying (QPSK) CDMA signals. In an experiment using a 128 degrees YX-LiNbO(3) substrate, CDMA signals of 9 Mbps (megabits per second) with 60 Mcps (megachips per second) spread by 13-chip Barker code and 11 Mbps with 140 Mcps spread by 25-chip Shiba's code were clearly demodulated, demonstrating the effectiveness of these techniques for use in future CDMA communications.
已经开发出具有高转换效率和自温度补偿特性的新型表面声波（SAW）卷积器结构。无论延迟温度系数（TCD）如何，强压电基板都可用于这些卷积器。还开发了使用所开发的SAW卷积器用于高比特率和宽带扩频码分多址（CDMA）通信的新解调技术。I和Q通道解调数据可直接从二进制相移键控（BPSK）或四相相移键控（QPSK）CDMA信号中导出。在使用128度YX-LiNbO(3)基板的实验中，由13芯片巴克码扩展的9 Mbps（兆比特每秒）和60 Mcps（兆码片每秒）的CDMA信号以及由25芯片芝波码扩展的11 Mbps和140 Mcps的CDMA信号被清晰解调，证明了这些技术在未来CDMA通信中使用的有效性。
