Carrier Generator

• US 20090295491A1
• Filed: 05/27/2008
• Published: 12/03/2009
• Est. Priority Date: 05/27/2008
• Status: Active Grant

• Current Assignee: FAVEPC, Inc.
• Original Assignee: FAVEPC, Inc.
• Inventors: Chang, Shao-Chang, Tsai, Chun-Liang
• Granted Patent: US 7,847,646 B2
• Time in Patent Office: Days
• US Class Current: 331/51
• CPC Class Codes: H03B 5/1215 the current source or degeneration circuit being in common to both transistors of the pair, e.g. a cross-coupled long-tailed pair
• CPC Class Codes: H03B 5/1228 the amplifier comprising one or more field effect transistors
• CPC Class Codes: H03B 5/1243 the means comprising voltage variable capacitance diodes
• CPC Class Codes: H03B 5/1265 switched capacitors
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H
• CPC Class Codes: H04L 27/0002 analog front ends; means for connecting modulators, demodulators or transceivers to a transmission line duplex arrangements H04L5/143

Abstract

A carrier generator for generating a carrier at a frequency of interest in a wireless communications system comprises an oscillator exhibiting a first impedance, the oscillator comprising an energy storage tank configured to generate a periodic signal, the energy storage tank including at least one inductor and at least one capacitor, and an amplifier coupled with the energy storage tank, the amplifier being configured to amplify an amplitude of the periodic signal, an antenna exhibiting a second impedance smaller than the first impedance, and a network coupled between the oscillator and the antenna, the network including at least one inductor or at least one capacitor and being configured to provide a third impedance such that a resultant impedance of the second impedance and the third impedance as viewed from the oscillator toward the antenna is large enough to facilitate the oscillator to generate the carrier at the frequency of interest.

Claims

1. A carrier generator for generating a carrier at a frequency of interest in a wireless communications system, the carrier generator comprising:

an oscillator exhibiting a first impedance, the oscillator comprising;

an energy storage tank configured to generate a periodic signal, the energy storage tank including at least one inductor and at least one capacitor; and

an amplifier coupled with the energy storage tank, the amplifier being configured to amplify an amplitude of the periodic signal;

an antenna exhibiting a second impedance smaller than the first impedance; and

a network coupled between the oscillator and the antenna, the network including at least one inductor or at least one capacitor and being configured to provide a third impedance such that a resultant impedance of the second impedance and the third impedance as viewed from the oscillator toward the antenna is large enough to facilitate the oscillator to generate the carrier at the frequency of interest.

2. The carrier generator of claim 1, wherein one of the at least one capacitor of the energy storage tank is a variable capacitor.

3. The carrier generator of claim 1 further comprising at least one trimming pin to adjust the at least one capacitor of the energy storage tank.

4. The carrier generator of claim 1 further comprising another oscillator configured to generate another periodic signal.

5. The carrier generator of claim 4 further comprising a phase frequency detector coupled to the other oscillator, wherein the phase frequency detector receives the other periodic signal from the other oscillator and the periodic signal from the oscillator via a frequency divider as inputs.

6. The carrier generator of claim 5 further comprising a finite state machine coupled to the phase frequency detector, wherein the finite state machine includes a number of “

N”

output bits.

7. The carrier generator of claim 6, wherein the at least one capacitor of the energy storage tank of the oscillator includes a number of N sets of capacitors coupled in parallel to one another.

8. The carrier generator of claim 1, wherein the oscillator includes a first output coupled to a first sub-network of the network, and a second output coupled to a second sub-network of the network.

9. The carrier generator of claim 1 further comprising:

a memory to store predetermined signals for frequency selection; and

a digital control circuit electrically connected between the memory and the oscillator, the digital control circuit being configured to retrieved the predetermined signals from the memory and send the same to the oscillator through at least one trimming pin.

10. The carrier generator of claim 9, wherein the memory further stores predetermined modulation data, and the digital control circuit being configured to retrieve the modulation data from the memory and send the same to the oscillator through at least one modulation pin.

11. A carrier generator for generating a carrier at a frequency of interest in a wireless communications system, the carrier generator comprising:

a first oscillator configured to generate a first periodic signal at a first frequency;

a second oscillator exhibiting a first impedance, the second oscillator comprising;

an energy storage tank configured to generate a second periodic signal based on the first periodic signal, the energy storage tank including at least one inductor and at least one capacitor; and

an amplifier coupled with the energy storage tank, the amplifier being configured to amplify an amplitude of the second periodic signal;

an antenna exhibiting a second impedance smaller than the first impedance; and

a network coupled between the second oscillator and the antenna, the network including at least one inductor or at least one capacitor and being configured to provide a third impedance such that a resultant impedance of the second impedance and the third impedance as viewed from the second oscillator toward the antenna is large enough to facilitate the second oscillator to generate the carrier at the frequency of interest.

12. The carrier generator of claim 11, wherein one of the at least one capacitor of the energy storage tank is a variable capacitor.

13. The carrier generator of claim 11 further comprising at least one trimming pin to adjust the at least one capacitor of the energy storage tank.

14. The carrier generator of claim 11 further comprising a phase frequency detector coupled to the first oscillator, wherein the phase frequency detector receives the first periodic signal from the first oscillator and the second periodic signal from the second oscillator via a frequency divider as inputs.

15. The carrier generator of claim 14 further comprising a finite state machine coupled to the phase frequency detector, wherein the finite state machine includes a number of “

N”

output bits.

16. The carrier generator of claim 15, wherein the at least one capacitor of the energy storage tank of the second oscillator includes a number of N sets of capacitors coupled in parallel to one another.

17. The carrier generator of claim 11, wherein the second oscillator includes a first output coupled to a first sub-network of the network, and a second output coupled to a second sub-network of the network.

18. A carrier generator for generating a carrier at a frequency of interest in a wireless communications system, the carrier generator comprising:

a first oscillator configured to generate the carrier, the first oscillator exhibiting a first impedance;

an antenna exhibiting a second impedance smaller than the first impedance; and

a network coupled between the first oscillator and the antenna, the network being configured to provide a third impedance such that a resultant impedance of the second impedance and the third impedance as viewed from the first oscillator toward the antenna facilitates the first oscillator to generate the carrier at the frequency of interest.

19. The carrier generator of claim 18, wherein the first oscillator comprises:

an energy storage tank configured to generate a first periodic signal, the energy storage tank including at least one inductor and at least one capacitor; and

an amplifier coupled with the energy storage tank, the amplifier being configured to amplify an amplitude of the first periodic signal to generate the carrier.

20. The carrier generator of claim 18, wherein the first oscillator includes a first output coupled to a first sub-network of the network, and a second output coupled to a second sub-network of the network.