Radio equipment directional coupler
AssigneeMotorola, Inc.
InventorLawrence R. Schumacher
Life of this patent
Estimating the term…
Abstract
A directional coupler (103) for radio equipment couples a radio frequency signal from an input of a microstrip transmission line (309) to an output and provides a directionally coupled output via a stripline microstrip (311). Open circuit microstrip transmission line stubs (313 and 315) are tuned to a quarter wavelength of the third harmonic of the radio frequency to provide third harmonic rejection within the directional coupler.
Claims13
A directional coupler for radio equipment, comprising:
- a first transmission line having an input port to which a radio signal may be applied and an output port;
- a second transmission line having at least a first port and coupled primarily to said first transmission line such that an attenuated portion of said radio signal is output at said first port;
- and
- a third transmission line having a distal end disposed away from said second transmission line, coupled at a proximal end primarily to said first transmission line and having an electrical length equal to an integer multiple of a quarter wavelength of an undesired component of said radio signal, whereby said undesired component is diminished at least at said output port.
A radio transmitter employing a directional coupler to couple the radio frequency output signal of the transmitter to an antenna and provide a signal representative of the coupled radio frequency output signal to a controller which controls the power of the radio frequency output signal, the directional coupler comprising:
- a first transmission line having an input port coupled to the transmitter and an output port coupled to the antenna;
- a second transmission line, coupled primarily to said first transmission line and having a first port coupled to the controller to provide a portion of said radio frequency output signal to the controller;
- and
- a third transmission line coupled primarily to said first transmission line and having an electrical length equal to an integer multiple of a quarter wavelength of an undesired component of said radio frequency output signal, whereby said undesired component is diminished at least at said output port.
A radio frequency power coupler comprising:
- a multilayer substrate having at least first, second, and internal surfaces;
- a first conductive material disposed on said first surface;
- a first conductive pattern disposed on said second surface and opposite said first conductive material and further comprising;
- (a) a first transmission line having an input port to which a radio frequency signal may be applied, and
- (b) a second transmission line coupled primarily to said first transmission line at a predetermined location and having an electrical length equal to an integer multiple of a quarter wavelength of an undesired component of said radio signal, whereby said undesired component is diminished at least at said output port;
- and
- a second conductive pattern disposed on said internal surface essentially opposite said first conductive material, coupled primarily to said first conductive pattern, and having at least one output port, whereby an attenuated portion of said radio frequency signal is output at said at least one output port.
Dependencies are inferred from the claim text.