Abstract: A communications device capable of simultaneously operating in a dual-band CDMA communications system having a cellular and a PCS CDMA communications systems and a dual-band GSM communications system having a GSM 900 and a GSM 1800 communications systems includes a radio signal transceiver module, a CDMA module, a GSM module, a first CDMA filtering unit, a second CDMA filtering unit, a first GSM filtering unit, and a second GSM filtering unit. The first CDMA filtering unit, the second CDMA filtering unit, the first GSM filtering unit, and the second GSM filtering unit are utilized for discarding signals in an overlapping frequency band between the dual-band CDMA and the dual-band GSM communications systems.

Abstract: A communications device capable of simultaneously operating in a dual-band CDMA communications system having a cellular and a PCS CDMA communications systems and a dual-band GSM communications system having a GSM 900 and a GSM 1800 communications systems includes a radio signal transceiver module, a CDMA module, a GSM module, a first CDMA filtering unit, a second CDMA filtering unit, a first GSM filtering unit, and a second GSM filtering unit. The first CDMA filtering unit, the second CDMA filtering unit, the first GSM filtering unit, and the second GSM filtering unit are utilized for discarding signals in an overlapping frequency band between the dual-band CDMA and the dual-band GSM communications systems.

Abstract: A communication device capable of operating in a first and a second communications systems includes a radio signal transceiver module, a first reception module for receiving signals from the first communications system, a first transmitting module for transmitting signals to the first communications system, a second reception module for receiving signals from the second communications system, a second transmitting module for transmitting signals to the second communications system, a first filtering unit coupled to the first transmitting module for filtering out signals in an overlapping frequency band between the first transmitting module and the second reception module, and a second filtering unit coupled to the second transmitting module for filtering out signals in an overlapping frequency band between the second transmitting module and the first reception module.