Adaptive antenna matching
First Claim
1. An adaptive antenna-matching network for a radiotelephone, said network comprising;
- first and second reactive circuits interconnected by a third reactive circuit, wherein each of said first and said second reactive circuits comprises a shunt element, and said third reactive circuit comprises a series reactance operative for reversal between capacitive and inductive values of reactance;
means responsive to the operating environment of the radiotelephone for directly measuring the level of reflected signals produced by the radio telephone'"'"'s environment;
means responsive to said level of reflected signals for electronically adjusting the impedances of individual ones of said reactive circuits of the matching network;
wherein said measuring means and said adjusting means are operative to effect repetitive measurements of the reflected signals and repetitive adjustments of the impedance.
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Accused Products
Abstract
In a mobile radio telephone, an adaptive impedance matching circuit (25) is positioned between a transmitting power amplifier (24) and a duplexer (18). The adaptive matching circuit (25) matches an antenna (17) to associated electronic circuitry, thereby optimising power transfer in an effort to maintain communication with a base station and to minimise power dissipation within the device itself. An adaptation algorithm is selected and implemented during idle periods when a reflection coefficient is identified as being large. The reactance of a passive pi network is incrementally modified and settings which achieve an optimum match are stored for subsequent use.
288 Citations
28 Claims
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1. An adaptive antenna-matching network for a radiotelephone, said network comprising;
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first and second reactive circuits interconnected by a third reactive circuit, wherein each of said first and said second reactive circuits comprises a shunt element, and said third reactive circuit comprises a series reactance operative for reversal between capacitive and inductive values of reactance; means responsive to the operating environment of the radiotelephone for directly measuring the level of reflected signals produced by the radio telephone'"'"'s environment; means responsive to said level of reflected signals for electronically adjusting the impedances of individual ones of said reactive circuits of the matching network; wherein said measuring means and said adjusting means are operative to effect repetitive measurements of the reflected signals and repetitive adjustments of the impedance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. An antenna-matching method for radiotelephones having an antenna-matching network, comprising the steps of:
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providing in said network first and second reactive circuits interconnected by a third reactive circuit, wherein each of said first and said second reactive circuits comprises a shunt element, and said third reactive circuit comprises a series reactance operative for reversal between capacitive and inductive values of reactance; measuring a level of reflected signals produced by the environment of a radiotelephone; and electronically adjusting an impedance of the matching network; wherein said adjusting step comprises steps of; electronically setting the reactance for said first reactive circuit in resonance when power is transmitted to the antenna; electronically setting said series reactance of said third reactive circuit in the network to a first predetermined reactance value; electronically adjusting the reactance of said second reactive circuit in the network over a range of reactive values; and selecting the optimum value for said second reactive circuit. - View Dependent Claims (19, 20, 21, 22)
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23. An antenna-matching method for radiotelephones having an antenna-matching network, comprising the steps of:
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measuring a level of reflected signals produced by the environment of a radiotelephone; and electronically adjusting an impedance of the matching network; wherein said adjusting step comprises steps of; electronically setting the reactance for a first parallel reactive circuit in the network resonance when power is transmitted to the antenna; electronically setting a series reactance circuit in the network to a first predetermined reactance value; electronically adjusting the reactance of a second parallel reactive circuit in the network over a range of reactive values; and selecting the optimum value for said second parallel reactive circuit; the method further comprising the steps of reversing the reactance of said series circuit from capacitive to inductive or vice versa after selecting said first optimum values; repeating said steps of adjusting said second parallel reactive circuit and selecting a second optimum value thereby; and selecting an optimum value providing the best reflection coefficient from said first and said second optimum values.
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24. An adaptive antenna-matching network for a radiotelephone, said network comprising:
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first and second reactive circuits interconnected by a third reactive circuit, wherein each of said first and said second reactive circuits comprises a shunt element, and said third reactive circuit comprises a series reactance operative for reversal between capacitive and inductive values of reactance; means responsive to the operating environment of the radiotelephone for directly measuring the level of reflected signals produced by the radio telephone'"'"'s environment; means responsive to said level of reflected signals for electronically adjusting the impedances of individual ones of said reactive circuits of the matching network.
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25. An adaptive antenna-matching network for a radiotelephone, said network comprising:
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a first reactive circuit having a shunt reactance and a second reactive circuit having a series reactance, said shunt reactance having a frequency-selectable resonance, and said series reactance being operative for reversal between capacitive and inductive values of reactance; means responsive to the operating environment of the radiotelephone for directly measuring the level of reflected signals produced by the radio telephone'"'"'s environment; and means responsive to said level of reflected signals for electronically adjusting the impedances of individual ones of said reactive circuits of the matching network.
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26. An adaptive antenna-matching network for a radiotelephone, said network comprising:
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first and second reactive circuits interconnected by a third reactive circuit, wherein each of said first and said second reactive circuits comprise a shunt reactance, and said third reactive circuit comprises a series reactance, one of said first and said second reactance circuits being operative to become transparent to a signal propagating through said antenna-matching network; means responsive to the operating environment of the radiotelephone for directly measuring the level of reflected signals produced by the radio telephone'"'"'s environment; and means responsive to said level of reflected signals for electronically adjusting the impedances of individual ones of said reactive circuits of the matching network.
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27. An antenna-matching method for radiotelephones having an antenna-matching network, comprising the steps of:
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providing in said network a first reactive circuit having a shunt reactance and a second reactive circuit having a series reactance, said shunt reactance having a frequency-selectable resonance, and said series reactance being operative for reversal between capacitive and inductive values of reactance; measuring a level of reflected signals produced by the environment of a radiotelephone; and electronically adjusting an impedance of the matching network; wherein said adjusting step comprises steps of; electronically setting the reactance for said first reactive circuit in resonance when power is transmitted to the antenna; electronically setting said series reactance of said second reactive circuit in the network to a first predetermined reactance value; electronically adjusting the reactance of said first reactive circuit in the network over a range of reactive values; and selecting the optimum value for said first reactive circuit.
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28. An antenna-matching method for radiotelephones having an antenna-matching network, comprising the steps of:
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providing in said network first and second reactive circuits interconnected by a third reactive circuit, wherein each of said first and said second reactive circuits comprise a shunt reactance, and said third reactive circuit comprises a series reactance, one of said first and said second reactance circuits being operative to become transparent to a signal propagating through said antenna-matching network; measuring a level of reflected signals produced by the environment of a radiotelephone; and electronically adjusting an impedance of the matching network; wherein said adjusting step comprises steps of; electronically setting the reactance for said first reactive circuit in resonance when power is transmitted to the antenna; electronically setting said series reactance of said third reactive circuit in the network to a first predetermined reactance value; electronically adjusting the reactance of said second reactive circuit in the network over a range of reactive values; and selecting the optimum value for said second reactive circuit.
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Specification