Carrier generator

Abstract

A carrier generator for generating a carrier at a frequency of interest in a wireless communications system. The carrier generator comprises a first oscillator configured to generate the carrier. The first oscillator exhibits a first impedance and comprises an energy storage tank, an amplifier, at least one trimming pin and at least one capacitor. The energy storage tank is configured to generate a first periodic signal. The energy storage tank includes at least one inductor and at least one capacitor. The amplifier coupled with the energy storage tank and is configured to amplify an amplitude of the first periodic signal. The at least one trimming pin is configured to adjust the at least one capacitor of the energy storage tank, and the at least one modulation pin is configured to receive a modulation signal. The carrier generator further comprises an antenna exhibiting a second impedance smaller than the first impedance, and a network coupled between the first oscillator and the antenna. The network includes 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 first oscillator toward the antenna is large enough to facilitate the first oscillator to generate the carrier at the frequency of interest.

1 . 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, the first oscillator comprising:
 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, 
 an amplifier coupled with the energy storage tank, the amplifier being configured to amplify an amplitude of the first periodic signal, 
 at least one trimming pin configured to adjust the at least one capacitor of the energy storage tank, and 
 at least one modulation pin configured to receive a modulation signal; 
   an antenna exhibiting a second impedance smaller than the first impedance; and   a network coupled between the first 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 first oscillator toward the antenna is large enough to facilitate the first 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 a second oscillator configured to generate a second periodic signal. 
     
     
         4 . The carrier generator of  claim 3  further comprising a phase frequency detector coupled to the second oscillator, wherein the phase frequency detector receives the second periodic signal from the second oscillator and the first periodic signal from the first oscillator via a frequency divider as inputs. 
     
     
         5 . The carrier generator of  claim 4  further comprising a finite state machine coupled to the phase frequency detector, wherein the finite state machine includes a number of “N” output bits. 
     
     
         6 . The carrier generator of  claim 5 , wherein the at least one capacitor of the energy storage tank of the first oscillator includes a number of N sets of capacitors coupled in parallel to one another. 
     
     
         7 . The carrier generator of  claim 1 , 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. 
     
     
         8 . 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 first oscillator, the digital control circuit being configured to retrieved the predetermined signals from the memory and send the same to the first oscillator through the at least one trimming pin.   
     
     
         9 . The carrier generator of  claim 8 , 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 first oscillator through the at least one modulation pin. 
     
     
         10 . The carrier generator of  claim 1 , wherein the at least one modulation pin configured to receive the modulation signal from a modulator.