Diplexer and multiplexer
AssigneeMicro Communications Corporation
InventorThomas J. Vaughan
Life of this patent
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Abstract
A plurality of different frequency signals f.sub.1, f.sub.2, f.sub.3, . . . fn are combined for transmission in a common transmission line by a series of hybrid circuits each including a through coupler for feeding through frequency signals through the hybrid circuit to the output thereof, an injection coupler for feeding an injected frequency signal to the hybrid output and one or more tuned circuits between the couplers that are tuned to the frequency of the injected frequency signal and connected to the couplers by a stub transmission line of electrical length in terms of wave lengths of the through frequency, so that substantially all power of the through frequency signal and all power of the injected frequency signal flow from the hybrid circuit output to the next hybrid circuit in the series.
Claims22
A high frequency signal combiner for combining the power of two different frequency signals ft and fi in a common transmission line comprising,
- (a) two directional couplers, an ft coupler and an fi coupler,
- (b) means for coupling ft to a port of the ft coupler
- (c) means for coupling fi to a port of the fi coupler,
- (d) an output to the common transmission line from a port of the fi coupler and
- (e) means including a transmission line stub and a tuned circuit for coupling together other ports of the ft and fi couplers that readily transmit ft signals from the ft coupler to the fi coupler while reflecting fi signals from the fi coupler back to the fi coupler,
- (f) whereby substantially all of the ft and fi signal power to the couplers is fed from the output to the common transmission line.
A high frequency multiplexer for combining the power of n different frequency signals f.sub.1, f.sub.2, f.sub.3, . . . fn in a common transmission line comprising,
- (a) a plurality of pairs of four port directional couplers, the pairs being coupled together in series,
- (b) each pair having two input ports called the through port and the injection port,
- (c) each pair having an output port,
- (d) the output port of each pair being coupled to the through port of the next pair in the series,
- (e) the output port of the last pair in the series being coupled to the common transmission line,
- (f) at least one other port of one coupler of a pair being coupled to another port of the other coupler of the pair by coupling means that readily transmits signals from the through port to the output port of the pair while reflecting signals from the injection port to the output port of the pair
- (g) said n different frequency signals being fed to selected injection ports in the series,
- (h) whereby the n signals are combined in the common transmission line.
In a high frequency diplexer for combining the powers of two frequency channels of carrier frequencies f.sub.1 and f.sub.2, to a single master antenna, where f.sub.1, called the through channel, is fed to the antenna via a through coupler and an injection coupler of the diplexer and f.sub.2, called the injected channel, is fed to the antenna via the injection coupler of the diplexer, the improvement comprising,
- (a) in selected coupling transmission lines between the through and injection couplers, a cavity that is resonant to f2 and not resonant to f.sub.1, connected to the selected transmission line by a stubb transmission line of electrical length that is three quarter wave length of f.sub.1,
- (b) whereby substantially all of f.sub.1 power flows through both couplers to the antenna and substantially all of f.sub.2 power flows through the injection coupler to the antenna.
Dependencies are inferred from the claim text.