Carrier generator with LC network

• US 7,847,646 B2
• Filed: 05/27/2008
• Issued: 12/07/2010
• Est. Priority Date: 05/27/2008
• Status: Expired due to Fees

• Current Assignee: FAVEPC, Inc.
• Original Assignee: FAVEPC, Inc.
• Inventors: Chang, Shao-Chang, Tsai, Chun-Liang
• Primary Examiner(s): Pascal; Robert
• Assistant Examiner(s): Johnson; Ryan
• Application Number:
  US12/127,527
• Publication Number:
  US 20090295491A1
• Time in Patent Office: 924 Days
• Field of Search: 331/74, 331/77, 331/167, 331/117.FE, 331/117.R, 331/179, 455/119, 455/126, 455/129, 332/100, 332/101, 332/102, 332/117, 332/127, 332/128, 332/126, 332/141
• US Class Current: 331/77
• 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;

a memory to store predetermined signals for frequency selection and predetermined modulation data;

a digital control circuit electrically connected between the memory and the oscillator, the digital control circuit being configured to retrieve the predetermined signals from the memory and send the same to the oscillator through at least one trimming pin, and to retrieve the modulation data from the memory and send the same to the oscillator through at least one modulation pin; 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, wherein the at least one trimming pin adjusts the at least one capacitor of the energy storage tank.

4. 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.

5. 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;

a memory to store predetermined signals for frequency selection and predetermined modulation data;

a digital control circuit electrically connected between the memory and the first oscillator, the digital control circuit being configured to retrieve the predetermined signals from the memory and send the same to the first oscillator through at least one trimming pin, and to retrieve the modulation data from the memory and send the same to the oscillator through at least one modulation pin;

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.

6. The carrier generator of claim 5, 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.

7. The carrier generator of claim 5, 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.