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A dual band user terminal (10) includes a controller (18) for outputting a BAND signal for specifying operation in one of a first frequency band or a second, higher frequency band; a single frequency synthesizer (46) that is responsive to the BAND signal for outputting an RF signal in one of two fre

A dual band user terminal (10) includes a controller (18) for outputting a BAND signal for specifying operation in one of a first frequency band or a second, higher frequency band; a single frequency synthesizer (46) that is responsive to the BAND signal for outputting an RF signal in one of two frequency bands; and an RF transceiver (11) comprising a dual band receiver that receives RF signals in the first frequency band and in the second, higher frequency band, and a dual band transmitter that transmits RF signals in the same frequency bands. The dual band receiver includes a first receiver chain that operates in the first frequency band as a single conversion receiver having a downconversion mixer that is preceded by a first filter and that is followed by second filter, and a second receiver chain that operates in the second frequency band as a dual conversion superheterodyne receiver having a first downconversion mixer preceded by a first filter and followed by a second filter coupled to a second downconversion mixer followed by a third filter. The downconversion mixer of the single conversion receiver is also the second downconversion mixer of the dual conversion superheterodyne receiver, and the second filter of the single conversion receiver is also the third filter of the dual conversion superheterodyne receiver. The dual band transmitter includes a modulator that outputs a modulated RF signal. When operating in the first frequency band the input RF signal to the modulator has a frequency that is equal to the transmitted RF signal, and when operating in the second frequency band the input RF signal has a frequency that is equal to one half of the transmitted RF signal.

대표청구항 ▼

[ What is claimed is:] [1.]1. A multiband user terminal, comprising:a controller for outputting a BAND signal for specifying operation in at least one of a first frequency band or a second, higher frequency band;a single frequency synthesizer that is responsive to said BAND signal for outputting a l

[ What is claimed is:] [1.]1. A multiband user terminal, comprising:a controller for outputting a BAND signal for specifying operation in at least one of a first frequency band or a second, higher frequency band;a single frequency synthesizer that is responsive to said BAND signal for outputting a local oscillator RF signal when operating in said first frequency band or said second frequency band; andan RF transceiver comprising a multiband receiver that receives RF signals in said first frequency band and in said second, higher frequency band, and a multiband transmitter that outputs a transmitted RF signal when operating in said first frequency band or in said second, higher frequency band, wherein said multiband transmitter comprisesa modulator that modulates said local oscillator RF signal in accordance with information to be transmitted and that outputs a modulated RF signal, wherein when operating in said first frequency band said local oscillator RF signal has a frequency that is equal to said transmitted RF signal, and wherein when operating in said second frequency band said local oscillator RF signal has a frequency that is equal to one half of said transmitted RF signal, and further comprising an upconversion mixer having a first input for receiving said modulated RF signal and a second input that receives said local oscillator RF signal, wherein said upconversion mixer upconverts said modulated RF signal, using said local oscillator RF signal, to have a frequency equal to said transmitted RF signal when operating in said second, higher frequency band,wherein said multiband receiver comprises a first receiver chain that operates in said first frequency band as a single conversion receiver having a downconversion mixer that is preceded by a first filter and that is followed by second filter, and further comprising a second receiver chain that operates in said second frequency band as a dual conversion superheterodyne receiver having a first downconversion mixer preceded by a first filter and followed by a second filter coupled to a second downconversion mixer followed by a third filter, wherein said downconversion mixer of said single conversion receiver is also said second downconversion mixer of said dual conversion superheterodyne receiver, and wherein said second filter of said single conversion receiver is also said third filter of said dual conversion superheterodyne receiver.