Filter switching circuit

Claim 2

A transceiver operative to receive wideband signals within a first bandwidth and narrowband signals of a second bandwidth, the transceiver comprising: an antenna; transmit circuitry coupled to the antenna for transmitting a transmit signal; and an integrated circuit upon which a drive circuit is disposed, the integrated circuit having a first input coupled to the antenna to receive the narrowband signals and the wideband signals, and the drive circuit coupled to the first input to receive the narrowband signals and wideband signals and operative to simultaneously generate a first isolated drive signal at a first output of the integrated circuit and a second isolated drive signal at a second output of the integrated circuit, wherein the first isolated drive signal and the second isolated drive signal generated at the first and second outputs of the integrated circuit, respectively, are isolated from one another; a wideband bandpass filter of the wideband bandwidth coupled to the first output of the integrated circuit and to a second input of the integrated circuit, the wideband bandpass filter operative to receive the first isolated drive signal generated by the drive circuit at the first output of the integrated circuit, to pass signal portions of the first isolated drive signal of frequencies within the wideband bandwidth, the signal portions of the first signal comprising the signal of the wideband bandwidth, and to apply the signal portions of the first isolated drive signal within the wideband bandwidth to the second input of the integrated circuit; a narrowband bandpass filter of the narrowband bandwidth coupled to the second output of the integrated circuit and to a third input of the integrated circuit, the narrowband bandpass filter operative to pass signal portions of the second isolated drive signal of frequencies within the narrowband bandwidth, the signal portions of the second signal comprising the signal of the narrowband bandwidth, and to apply the signal portions of the second isolated drive signal within the narrowband bandwidth to the third input of the integrated circuit; a first amplification circuit disposed upon the integrated circuit upon which the drive circuit is disposed and coupled to receive the signal portions of the first isolated drive signal passed by the wideband bandpass filter; a second amplification circuit disposed upon the integrated circuit upon which the drive circuit and the first amplification circuit are disposed and coupled to receive the signal portions of the second isolated drive signal passed by the narrowband bandpass filter; and a switching circuit coupled to the first amplification circuit and to the second amplification circuit for alternately permitting powering of the first amplification circuit or of the second amplification circuit, thereby for permitting, alternately, passage of the signal of the wideband bandwidth or the signal of the narrowband bandwidth.

Claim 3

The transceiver as defined in claim 1, wherein the narrowband bandpass filter and the wideband bandpass filter are discrete ceramic filters.

Claim 4

A dual-bandwidth filter switching circuit connected to a first discrete filter of a first bandwidth and to a second discrete filter of a second bandwidth, the filter switching circuit operative to pass a signal of either a first bandwidth corresponding to the first bandwidth of the first discrete filter or a signal of a second bandwidth corresponding to the second bandwidth of the second discrete filter responsive to application of an input signal to the filter switching circuit, the first and second bandwidths not being equal, the filter switching circuit comprising: a drive circuit disposed upon an integrated circuit having a first input coupled to receive the input signal and operative to generate a first isolated drive signal at a first output of the integrated circuit for application to the first discrete filter and a second drive signal at a second output of the integrated circuit for application to the second discrete filter wherein the first isolated drive signal and the second isolated drive signal generated at the first and second outputs, respectively, of the integrated circuit are isolated from one another, and wherein a first signal path is coupled to an input of the first filter and a second signal path is coupled to an input of the second filter; a first amplification circuit disposed upon the integrated circuit upon which the drive circuit is disposed and coupled at a second input of the integrated circuit to an output of the first discrete filter thereby to receive the signal of the first bandwidth passed by the first discrete filter, the first amplification circuit being operative to generate a first amplified signal of the first bandwidth at a third output of the integrated circuit; a second amplification circuit disposed upon the integrated circuit upon which the drive circuit and the first amplification circuit are disposed and coupled at a third input of the integrated circuit to an output of the second discrete filter thereby to receive the signal of the second bandwidth passed by the second discrete filter, the second amplification circuit being operative to generate a second amplified signal of the second bandwidth at a fourth output of the integrated circuit; and a switching circuit disposed upon the integrated circuit upon which the drive circuit and the first and second amplification circuits are disposed, the switching circuit coupled to the first amplification circuit and to the second amplification circuit for alternately permitting powering of the first amplification circuit or of the second amplification circuit, thereby for permitting, alternately, passage of the first amplified signal of the first bandwidth or the second amplified signal of the second bandwidth.

Claim 5

A dual-bandwidth filter switching circuit connected to a first discrete filter of a first bandwidth and to a second discrete filter of a second bandwidth, the filter switching circuit operative to pass a signal of either a first bandwidth corresponding to the first bandwidth of the first discrete filter or a signal of a second bandwidth corresponding to the second bandwidth of the second discrete filter responsive to application of an input signal to the filter switching circuit, the first and second bandwidths not being equal, the filter switching circuit comprising: a drive circuit disposed upon an integrated circuit having a first input coupled to receive the input signal and operative to generate a first isolated drive signal at a first output of the integrated circuit for application to the first discrete filter and a second drive signal at a second output of the integrated circuit for application to the second discrete filter wherein the first isolated drive signal and the second isolated drive signal generated at the first and second outputs, respectively, of the integrated circuit are isolated from one another, and wherein a first signal path is coupled to an input of the first filter and a second signal path is coupled to an input of the second filter; a first amplification circuit disposed upon the integrated circuit upon which the drive circuit is disposed and coupled at a second input of the integrated circuit to an output of the first discrete filter thereby to receive the signal of the first bandwidth passed by the first discrete filter, the first amplification circuit being operative to generate a first amplified signal of the first bandwidth at a third output of the integrated circuit; a second amplification circuit disposed upon the integrated circuit upon which the drive circuit and the first amplification circuit are disposed and coupled at a third input of the integrated circuit to an output of the second discrete filter thereby to receive the signal of the second bandwidth passed by the second discrete filter, the second amplification circuit being operative to generate a second amplified signal of the second bandwidth at a fourth output of the integrated circuit; and a switching circuit disposed upon the integrated circuit upon which the drive circuit and the first and second amplification circuits are disposed, the switching circuit coupled to the first amplification circuit and to the second amplification circuit for alternately permitting powering of the first amplification circuit or of the second amplification circuit, thereby for permitting, alternately, passage of the first amplified signal of the first bandwidth or the second amplified signal of the second bandwidth.

Claim 6

A radio receiver circuit operative to selectively pass a signal of either a wideband or a narrowband for processing by the radio receiver, comprising: an integrated circuit including a drive circuit, the integrated circuit having a first input coupled to an antenna to receive a received signal, the drive circuit having an input coupled to the first input of the integrated circuit to receive the received signal and operative to generate a first isolated drive signal at a first output of the integrated circuit and a second isolated drive signal at a second output of the integrated circuit, wherein the first isolated drive signal and the second isolated drive signal are maintained in isolation with one another; a discrete ceramic bandpass filter of a wideband bandwidth coupled to the first output of the integrated circuit to receive the first isolated drive signal generated by the drive circuit, the discrete ceramic bandpass filter operative to pass signal portions of the first isolated drive signal of frequencies within the wideband bandwidth, the discrete ceramic bandpass filter having an output coupled to a second input of the integrated circuit; a discrete ceramic narrowband bandpass filter of a narrowband bandwidth coupled to the second output of the integrated circuit to receive the second isolated drive signal generated by the drive circuit, the discrete ceramic narrowband bandpass filter operative to pass signal portions of the second isolated drive signal of frequencies within the narrowband bandwidth, the discrete narrowband bandpass filter having an output coupled to a third input of the integrated circuit; a first amplification circuit disposed upon the integrated circuit upon which the drive circuit is disposed and coupled to the second input of the integrated circuit to receive the signal portions of the first isolated drive signal passed by the discrete ceramic wideband bandpass filter, the first amplification circuit being operative to generate a first amplified signal of the wideband bandwidth at a third output of the integrated circuit; a second amplification circuit disposed upon the integrated circuit upon which the drive circuit and the first amplification circuit are disposed and coupled to the third input of the integrated circuit to receive the signal portions of the second signal passed by the discrete ceramic narrowband bandpass filter, the second amplification circuit being operative to generate a second amplified signal of the narrowband bandwidth at a fourth output of the integrated circuit; and a switching circuit disposed upon the integrated circuit upon which the drive circuit and the first and second amplification circuits are disposed, the switching circuit coupled to the first amplification circuit and to the second amplification circuit for alternately permitting powering of the first amplification circuit or of the second amplification circuit, thereby for alternately permitting passage of the signal of the wideband bandwidth or the signal of the narrowband bandwidth.

Claim 7

A radio receiver circuit operative to selectively pass a signal of either a wideband or a narrowband for processing by the radio receiver, comprising: an integrated circuit including a drive circuit, the integrated circuit having a first input coupled to an antenna to receive a received signal, the drive circuit having an input coupled to the first input of the integrated circuit to receive the received signal and operative to generate a first isolated drive signal at a first output of the integrated circuit and a second isolated drive signal at a second output of the integrated circuit, wherein the first isolated drive signal and the second isolated drive signal are maintained in isolation with one another; a discrete ceramic bandpass filter of a wideband bandwidth coupled to the first output of the integrated circuit to receive the first isolated drive signal generated by the drive circuit, the discrete ceramic bandpass filter operative to pass signal portions of the first isolated drive signal of frequencies within the wideband bandwidth, the discrete ceramic bandpass filter having an output coupled to a second input of the integrated circuit; a discrete ceramic narrowband bandpass filter of a narrowband bandwidth coupled to the second output of the integrated circuit to receive the second isolated drive signal generated by the drive circuit, the discrete ceramic narrowband bandpass filter operative to pass signal portions of the second isolated drive signal of frequencies within the narrowband bandwidth, the discrete narrowband bandpass filter having an output coupled to a third input of the integrated circuit; a first amplification circuit disposed upon the integrated circuit upon which the drive circuit is disposed and coupled to the second input of the integrated circuit to receive the signal portions of the first isolated drive signal passed by the discrete ceramic wideband bandpass filter, the first amplification circuit being operative to generate a first amplified signal of the wideband bandwidth at a third output of the integrated circuit; a second amplification circuit disposed upon the integrated circuit upon which the drive circuit and the first amplification circuit are disposed and coupled to the third input of the integrated circuit to receive the signal portions of the second signal passed by the discrete ceramic narrowband bandpass filter, the second amplification circuit being operative to generate a second amplified signal of the narrowband bandwidth at a fourth output of the integrated circuit; and a switching circuit disposed upon the integrated circuit upon which the drive circuit and the first and second amplification circuits are disposed, the switching circuit coupled to the first amplification circuit and to the second amplification circuit for alternately permitting powering of the first amplification circuit or of the second amplification circuit, thereby for alternately permitting passage of the signal of the wideband bandwidth or the signal of the narrowband bandwidth.

Claim 8

The radio receiver filter switching circuit of claim 4 wherein the switching circuit comprises transistor switches.