Patent ID: 7013121
Filing Date: 2006-03-14
Classification: H04B

Abstract:
1. An apparatus for microwave radio frequency communication wherein an upstream radio frequency (RF) band is used for transmitting signals in an upstream direction, and a downstream radio frequency band is used for receiving signals in a downstream direction, the apparatus comprising: an up-converter comprising at least two up-converter stages, each up-converter stage including a mixer, and each mixer accepting a respective local oscillator signal wherein a final up-converter stage is connected to provide a transmit RF upstream signal; a down-converter, comprising at least two down-converter stages, each down-converter stage including a mixer and accepting a respective local oscillator signal wherein a first down-converter stage is connected to receive a receive RF downstream signal; the mixers in the first down-converter stage and the final up-converter stage being connected to receive a common local oscillator signal; a local reference oscillator, for providing a local reference signal; a first frequency multiplier circuit, connected to receive the local reference signal, and to provide the common local oscillator signal at a frequency which is an integer multiple of the local reference signal; wherein the local reference signal is also to derive the local oscillator signal coupled to one of the mixers in a down-converter stage which is not the first down-converter stage, or the local reference signal is used to derive the local oscillator signal coupled to one of the mixers in an up-converter stage which is not the final up-converter stage; and wherein the local reference signal is fed to a second frequency-multiplier circuit to provide the local oscillator signal coupled to the mixer in the final down-converter stage.