US 7,966,140 B1 · Radio frequency power meter

Abstract

An in-line directional radio-frequency (“RF”) power meter for measuring power and other parameters in a transmission line. The meter simultaneously measures complex voltage-waves traveling in the forward and reverse directions of a connected transmission line and processes measured voltages to compute forward and reverse power, standing wave ratio, and impedance values. The apparatus includes a microprocessor having microcode for digitally computing RF power parameters, and a field programmable gate array (“FPGA”) having microcode for executing complex Fast Fourier Transforms (“FFT”) to calculate voltages and frequencies, a microprocessor with attached firmware to make a series of complex calculations relative to sensed electrical values in the transmission line and to pass certain calculated values to the device to communicate RF power parameters to a user. The configuration of the apparatus allows for measurement of RF power parameters in a relatively economical package.

Claims22

Dependent claims

An apparatus for measuring radio frequency power parameters in a radio frequency transmission system having a radio frequency source and a radio frequency load, comprising:

a. connectors for electrically interposing said apparatus between said source and said load;
b. a semi-directional coupler for electrically receiving a first signal and a second signal from said transmission system through said connectors;
c. at least one electrical filter applied to at least one of said first and second signals for compensating for the frequency dependant coupling nature of said electrical coupler;
d. an A-D converter for sampling said filtered first and second signals;
e. a signal processing module for making complex calculations on said sampled filtered first and second signals;
and,
f. means running on said processing module for calculating a power of a radio signal propagated through said transmission system from said source, said power calculating means including means for calculating an ambiguous frequency estimate for said first and second signal, means for converting said ambiguous frequency estimate into an unambiguous value, means for calculating complex amplitudes of said first and second signal, means for mathematically compensating for limitations of said semi-directional coupler, and using interim calculation results from said ambiguous frequency estimate calculating means, said converting means, said calculating complex amplitudes means, and said compensating means for calculating power parameters in said system and outputting said power parameters for further human use.

4 more elements

A method for measuring radio frequency power parameters in a radio frequency power transmission system having a radio frequency source and a radio frequency load, comprising the steps of:

a. receiving a first signal and a second signal through a semi-directional coupler electrically connected to said transmission system;
b. filtering said first signal and second signal to facilitate digitization of said signals;
c. digitally sampling said filtered first and second signals to create a digital representation of said first and second signals;
d. calculating a plurality of ambiguous frequency estimates of said first and second digital signals;
e. converting said ambiguous frequency estimates of said first and second digital signals into an unambiguous frequency value;
f. identifying variable coefficients from a calibration table;
g. calculating the complex amplitudes of said first and second digital signals responsive to said coefficient identification step;
h. mathematically compensating for inherent limitations of said coupler;
and
i. responsive to said step of converting ambiguous frequency estimates into unambiguous frequency value and said step of calculating said complex amplitudes of said first and second digital signals, calculating power parameters representative of transmission power exhibited by said radio power transmission system.

7 more elements

An apparatus for measuring radio frequency power parameters in a radio frequency transmission system having forward and reverse traveling signals relative to a radio frequency source and a radio frequency load, comprising:

a. means for electrically connecting said apparatus to said transmission system such that said apparatus is electrically interposed between said source and said load;
b. means for passing said reverse and forward traveling signals through a semi-directional coupler from said connecting means to produce a left and right signal;
c. filter means connected to said semi-directional coupler for compensating for the frequency dependant coupling nature of said semi-directional coupler in each said right and left signal;
d. converter means for digitally sampling said filtered right and left signals;
e. signal processing means for making complex calculations on said sampled and filtered right and left signals;
and,
f. means running on said processing means for calculating a power of a radio signal propagated through said transmission system from said source, said power calculating means including means for calculating an ambiguous frequency estimate for said forward and reverse signals, means for converting said ambiguous frequency estimate into an unambiguous value, means for calculating complex amplitudes of said forward and reverse signals, means for mathematically compensating for limitations of said semi-directional coupler, and using interim calculation results from said ambiguous frequency estimate calculating means, said converting means, said complex amplitudes calculating means, and said compensating means for calculating power parameters in said transmission system and outputting said power parameters for further human use.

4 more elements

Dependencies are inferred from the claim text.

Radio frequency power meter

Life of this patent

Radio frequency power meter

Life of this patent

Abstract

Claims22