Apparatus for Antenna Impedance-Matching and Associated Methods
An apparatus includes an impedance matching circuit for matching an impedance of a high quality factor (high-Q) antenna to an impedance of a radio-frequency (RF) circuit. The impedance matching network includes a first reactive network. The impedance matching network also includes a second reactive network coupled in series with the first reactive network. The second reactive network includes a reactive component realized by multiple reactive components so as to reduce sensitivity of the impedance matching network to component tolerances in the second reactive network.
1 . An apparatus, comprising:
an impedance matching circuit for matching an impedance of a high quality factor (high-Q) antenna to an impedance of a radio-frequency (RF) circuit, the impedance matching network comprising:
a first reactive network; and
a second reactive network coupled in series with the first reactive network, wherein the second reactive network includes a reactive component realized by multiple reactive components so as to reduce sensitivity of the impedance matching network to component tolerances in the second reactive network.
2 . The apparatus according to claim 1 , wherein the reactive component realized by multiple reactive components comprises a capacitor realized by a plurality of series-coupled capacitors.
3 . The apparatus according to claim 2 , wherein the impedance matching circuit matches the impedance of an inductive high-Q antenna to the impedance of RF circuit.
4 . The apparatus according to claim 1 , wherein the reactive component realized by multiple reactive components comprises an inductor realized by a plurality of series-coupled inductors.
5 . The apparatus according to claim 4 , wherein the impedance matching circuit matches the impedance of a capacitive high-Q antenna to the impedance of RF circuit.
6 . The apparatus according to claim 1 , wherein the RF circuit comprises receive (RX) circuitry and/or transmit (TX) circuitry.
7 . An apparatus, comprising:
an impedance matching circuit for matching an impedance of a high quality factor (high-Q) antenna to an impedance of a radio-frequency (RF) circuit, the impedance matching network comprising:
a reactive network comprising at least one reactive component; and
a resonant network coupled in shunt with the reactive network, wherein a reactance of the resonant tank as a function of frequency varies in an opposite manner of a reactance of the reactive network.
8 . The apparatus according to claim 7 , wherein the resonant network comprises an inductor coupled in parallel with a capacitor.
9 . The apparatus according to claim 7 , wherein the resonant network comprises a plurality of inductors coupled in parallel with a respective plurality of capacitors.
10 . The apparatus according to claim 7 , wherein the reactive network comprises at least one inductor.
11 . The apparatus according to claim 7 , wherein the reactive network comprises an inductor split into a plurality of inductors in order to reduce sensitivity of the impedance matching circuit to component tolerances.
12 . The apparatus according to claim 7 , wherein the reactive network comprises at least one capacitor.
13 . The apparatus according to claim 7 , wherein the reactive network comprises a capacitor split into a plurality of capacitors in order to reduce sensitivity of the impedance matching circuit to component tolerances.
14 . An apparatus, comprising:
an impedance matching circuit for matching an impedance of a high quality factor (high-Q) antenna to an impedance of a radio-frequency (RF) circuit, the impedance matching network comprising:
a reactive network comprising at least one reactive component; and
a resonant network coupled in series with the reactive network, wherein a reactance of the resonant tank as a function of frequency varies in an opposite manner of a reactance of the reactive network.
15 . The apparatus according to claim 14 , wherein the resonant network comprises an inductor coupled in series with a capacitor.
16 . The apparatus according to claim 14 , wherein the resonant network comprises a plurality of inductors coupled in series with a respective plurality of capacitors.
17 . The apparatus according to claim 14 , wherein the reactive network comprises at least one inductor.
18 . The apparatus according to claim 14 , wherein the reactive network comprises an inductor split into a plurality of inductors in order to reduce sensitivity of the impedance matching circuit to component tolerances.
19 . The apparatus according to claim 14 , wherein the reactive network comprises at least one capacitor.
20 . The apparatus according to claim 14 , wherein the reactive network comprises a capacitor split into a plurality of capacitors in order to reduce sensitivity of the impedance matching circuit to component tolerances.