Radio interference suppression circuit and method, antenna multiplexer, transceiver circuit, and communication apparatus
First Claim
1. A radio interference suppression circuit used in a radio circuit performing duplex transmission in all or part of communication, comprising:
- first branching means of receiving a transmission frequency signal and then bifurcating and outputting the signal into at least two outputs at a predetermined branching ratio; and
second branching means which acquires, through one input thereof, a signal containing a received reception frequency signal and the leakage signal component of a transmission frequency signal to be transmitted, and acquires, through the other input thereof, the transmission frequency signal outputted from one output of said first branching means, and which combines and outputs these acquired signals at a predetermined combining ratio;
wherein;
a transmission frequency signal to be transmitted is outputted from an other output of said first branching means;
the signal from said second branching means is inputted to a receiving circuit; and
the leakage signal component of said transmission frequency signal to be transmitted which is contained in said signal inputted through the one input of said second branching means and said transmission frequency signal inputted through the other input of said second branching means are adjusted to be substantially of equal amplitude and reversed phase.
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Accused Products
Abstract
A radio interference suppression circuit used in a radio circuit of performing duplex transmission, comprises a first directional coupler of receiving a transmission frequency signal and then bifurcating and outputting the signal; and a second directional coupler which acquires, through one input thereof, a signal outputted from a reception filter of an antenna multiplexer and containing a reception frequency signal and the leakage signal component of a transmission frequency signal, and acquires, through the other input thereof, the transmission frequency signal outputted from one output of the first directional coupler, and which combines and outputs these acquired signals; wherein the leakage signal component of the transmission frequency signal contained in the signal inputted through the one input of the second directional coupler and the transmission frequency signal inputted through the other input of the second directional coupler are adjusted to be substantially of equal amplitude and reversed phase.
33 Citations
12 Claims
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1. A radio interference suppression circuit used in a radio circuit performing duplex transmission in all or part of communication, comprising:
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first branching means of receiving a transmission frequency signal and then bifurcating and outputting the signal into at least two outputs at a predetermined branching ratio; and
second branching means which acquires, through one input thereof, a signal containing a received reception frequency signal and the leakage signal component of a transmission frequency signal to be transmitted, and acquires, through the other input thereof, the transmission frequency signal outputted from one output of said first branching means, and which combines and outputs these acquired signals at a predetermined combining ratio;
wherein;
a transmission frequency signal to be transmitted is outputted from an other output of said first branching means;
the signal from said second branching means is inputted to a receiving circuit; and
the leakage signal component of said transmission frequency signal to be transmitted which is contained in said signal inputted through the one input of said second branching means and said transmission frequency signal inputted through the other input of said second branching means are adjusted to be substantially of equal amplitude and reversed phase. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A radio interference suppression method comprising the steps of:
- branching a portion of a transmission frequency signal outputted from a transmitting circuit; and
adding (1) a transmission frequency signal having leaked into a receiving circuit through a transmission-reception branch point which is a connection point between a transmission system and a reception system, and said branched portion of the transmission frequency signal to each other substantially with each having equal amplitude and reversed phase.
- branching a portion of a transmission frequency signal outputted from a transmitting circuit; and
Specification