US 4,034,289 AGranted

RF power monitor utilizing bi-directional coupler

AssigneeMotorola, Inc.

InventorsEdward Francis Rozylowicz, Steven Glen Twiselton

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Abstract

The coupler inserts in an RF transmission line and produces a pair of DC signals whose level is representative of the magnitude of forward or reverse power flow therethrough. Power flow is sensed via a pair of non resonant loops, each of which is terminated and oriented such that AC signals, whose amplitudes correspond to the forward or reverse power flow magnitude, are produced. Since the RF signals produced by the loops are dependent on the RF power flow frequency, unique circuitry processes the RF signals and compensates for this frequency dependence whereby the processed AC signals are substantially frequency independent. Also disclosed are improved rectification circuitry, and a means to compensate the coupler against error due to thermal drift of coupler components.

Claims12

Dependent claims

In a means for monitoring an RF power line and producing a signal representative of the power flow thereon, apparatus comprising:

reactance coupling means, electrically coupled to the power line in a low power loss configuration, and producing a signal whose magnitude is dependent on the magnitude of power flow on the power line, said reactance coupling means produced signal magnitude also being dependent on the frequency of the RF power line flow;
frequency compensating means for processing the reactance coupling means produced signal and predeterminedly compensating the magnitude thereof in response to the frequency of the RF power flow, such that the magnitude of the frequency compensating means processed signal is substantially independent of the frequency of the RF power line flow over a given frequency range,
rectifier means for rectifying and filtering the processed signal to produce a DC signal having a magnitude representative of the magnitude of the RF power flow, said rectifier means including one or more elements which display thermal drift characteristics;
and
diode means for compensating said DC produced signal against thermal drift.

2 more elements

A coupler for insertion in an RF power line and producing a pair of DC signals, the first DC signal having an amplitude representative of the magnitude of power flow on the line in the forward direction, the second DC signal having an amplitude representative of the magnitude of power flow in the reverse direction, the coupler comprising:

first reactive coupling means for producing a first AC signal whose amplitude is dependent on the magnitude and frequency of the RF power flow in the forward direction;
second reactive coupling means for producing a second AC signal whose amplitude is dependent on the magnitude and frequency of the RF power flow in the reverse direction;
first frequency compensating means for processing said first AC signal and predeterminedly compensating the amplitude thereof in response to the RF power flow frequency such that the amplitude of the processed first AC signal is substantially independent of the RF power flow frequency;
second frequency compensating means for processing said second AC signal and predeterminedly compensating the amplitude thereof in response to the RF power flow frequency such that the amplitude of the processed second AC signal is substantially independent of the RF power flow frequency;
first rectification means for receiving the compensated first AC signal and producing a first DC signal representative of the amplitude thereof;
second rectification means for receiving the compensated second AC signal and producing a second DC signal representative of the amplitude thereof;
and
diode means for compensating both the first and second DC voltages against thermal drift.

5 more elements

Dependencies are inferred from the claim text.