Antenna Tuning
Disclosed are various embodiments for tuning an antenna. Multiple phase sets for a tuning circuit impedance are generated. Each phase set includes multiple phase values. A reflected voltage corresponding to each of the phase values is determined. For each phase set, one of the phase values is selected based on the corresponding reflected voltage. The phase values for each phase set that is subsequent to an initial phase set are generated. The phase values are based on the selected phase value for the previous the phase set.
1 . A system, comprising:
a transmitter;
an antenna in communication with the transmitter; and
tuning circuitry for the antenna, the tuning circuitry being configured to:
generate a plurality of phase sets for an impedance of the tuning circuitry, each of the phase sets comprising a plurality of phase values;
select one of the phase values for each of the phase sets, the selected one of the phase values being based on a reflected voltage corresponding to each of the phase values; and
generate the phase values for each of the phase sets subsequent to an initial one of the phase sets, the phase values being based on the selected one of the phase values of a previous one of the phase sets.
2 . The system of claim 1 , wherein the tuning circuitry is further configured to select a magnitude of a reflection coefficient for the impedance of the tuning circuitry based on a predetermined source impedance of the transmitter.
3 . The system of claim 2 , wherein the magnitude of the reflection coefficient for the impedance is further selected based on a ratio of the reflected voltage to a forward voltage for the antenna.
4 . The system of claim 1 , wherein the previous one of the phase sets is an immediately previous one of the phase sets.
5 . The system of claim 1 , wherein a difference between the phase values for each of the phase sets decreases for each subsequent one of the phase sets.
6 . The system of claim 1 , wherein the tuning circuitry is further configured to configure a load impedance for the transmitter to substantially match a source impedance upon the reflected voltage being within a predetermined threshold, the load impedance comprising the impedance of the tuning circuitry and an antenna impedance, the load impedance being based on a final one of the selected one of the phase values.
7 . The system of claim 1 , wherein the tuning circuitry is further configured to configure a load impedance for the transmitter to substantially match a source impedance upon a predetermined number of the phase sets being generated, the load impedance comprising the impedance of the tuning circuitry and an antenna impedance, the load impedance being based on a final one of the selected one of the phase values.
8 . An apparatus, comprising:
circuitry configured to select a magnitude of a reflection coefficient for an impedance of a tuning circuit for an antenna;
circuitry configured to generate a plurality of phase sets for the impedance of the tuning circuit, each of the phase sets comprising a plurality of phase values;
circuitry configured to determine a reflected voltage in response to using the magnitude of the reflection coefficient and the phase values of each of the phase sets for the impedance of the tuning circuit;
circuitry configured to select, for each of the phase sets, one of the phase values based on the corresponding reflected voltage; and
circuitry configured to generate the phase values for each of the phase sets subsequent to an initial one of the phase sets, the phase values being based on the selected one of the phase values of a previous one of the phase sets.
9 . The apparatus of claim 8 , wherein the previous one of the phase sets is an immediately previous one of the phase sets.
10 . The apparatus of claim 8 , wherein a difference between the phase values for each of the phase sets decreases for each subsequent one of the phase sets.
11 . The apparatus of claim 8 , further comprising circuitry configured to configure a load impedance to substantially match a source impedance upon the reflected voltage being within a predetermined threshold, the load impedance comprising the impedance of the tuning circuit and an antenna impedance, the load impedance being based on a final one of the selected one of the phase values.
12 . The apparatus of claim 8 , further comprising circuitry configured to configure a load impedance to substantially match a source impedance upon a predetermined number of the phase sets being generated, the load impedance comprising the impedance of the tuning circuit and an antenna impedance, the load impedance being based on a final one of the selected one of the phase values.
13 . The apparatus of claim 8 , wherein the magnitude of the reflection coefficient for the impedance of the tuning circuit is based on a predetermined source impedance.
14 . The apparatus of claim 13 , wherein the magnitude of the reflection coefficient for the impedance of the tuning circuit is further based on a ratio of the reflected voltage to a forward voltage for the antenna.
15 . A method, comprising:
generating, in a circuit, a plurality of phase sets for an impedance of a tuning circuit for an antenna, each phase set comprising a plurality of phase values;
determining, in the circuit, a reflected voltage in response to using each of the phase values of each of the phase sets for the impedance of the tuning circuit;
selecting, in the circuit, for each of the phase sets, one of the phase values based on the corresponding reflected voltage; and
generating, in the circuit, the phase values for each of the phase sets subsequent to an initial one of the phase sets, the phase values being based on the selected one of the phase values of a previous one of the phase sets.
16 . The method of claim 15 , wherein a difference between the phase values for each of the phase sets decreases for each subsequent one of the phase sets.
17 . The method of claim 15 , wherein generating the phase values for each of the phase sets is stopped in response to the reflected voltage being within a predetermined threshold.
18 . The method of claim 15 , wherein generating the phase values is stopped upon a completion of a predetermined number of a plurality of iterations of generating the phase values
19 . The method of claim 15 , further comprising selecting, in the circuit, a magnitude of a reflection coefficient for the impedance of the tuning circuit based on a predetermined source impedance.
20 . The method of claim 19 , wherein the magnitude of the reflection coefficient for the impedance is further based on a ratio of the reflected voltage to a forward voltage for the antenna.