Quadrature oscillator and methods thereof

Abstract

A quadrature oscillator includes a master tuned oscillator and two injection-locked slave tuned oscillators.

1 . A method comprising: 
 generating quadrature signals from substantially anti-phase output signals of a source oscillator oscillating at a frequency, said output signals having substantially twice said frequency, said quadrature signals having substantially half said frequency and having a phase difference therebetween of substantially π/2 radians.    
   
   
       2 . The method of  claim 1 , wherein generating said quadrature signals comprises: 
 tuning slave oscillators coupled to said source oscillator to have a natural self-resonant frequency within an injection-locking range to said frequency.    
   
   
       3 . The method of  claim 1 , wherein generating said quadrature signals comprises: 
 injecting said output signals to single-ended inputs of tuned slave oscillators.    
   
   
       4 . The method of  claim 1 , wherein generating said quadrature signals comprises: 
 injecting said output signals to differential inputs of tuned slave oscillators.    
   
   
       5 . An apparatus comprising: 
 a quadrature oscillator including at least a source oscillator able to oscillate at a frequency and to produce substantially anti-phase output signals at said frequency, said quadrature oscillator able to generate quadrature signals from said output signals, said quadrature signals having substantially half said frequency and having a phase difference therebetween of substantially π/2 radians.    
   
   
       6 . The apparatus of  claim 5 , wherein said quadrature oscillator further includes two slave oscillators having input nodes coupled to output nodes of said source oscillator.  
   
   
       7 . The apparatus of  claim 6 , wherein said input nodes are coupled to said output nodes via a single-ended connection scheme.  
   
   
       8 . The apparatus of  claim 6 , wherein said input nodes are coupled to said output nodes via a differential connection scheme.  
   
   
       9 . The apparatus of  claim 6 , wherein the architecture of each of said slave oscillators is similar to the architecture of said source oscillator.  
   
   
       10 . The apparatus of  claim 6 , wherein said slave oscillators are tuned oscillators.  
   
   
       11 . The apparatus of  claim 6 , wherein at least one of said slave oscillators includes at least one shunt resonant circuit tuned to twice said frequency.  
   
   
       12 . The apparatus of  claim 6 , further comprising a matching network coupling said slave oscillators to said source oscillator.  
   
   
       13 . The apparatus of  claim 5 , wherein said source oscillator is a tuned oscillator.  
   
   
       14 . A communication device comprising: 
 a dipole antenna; and    a quadrature oscillator including at least a source oscillator able to oscillate at a frequency and to produce substantially anti-phase output signals at said frequency, said quadrature oscillator able to generate quadrature signals from said output signals, said quadrature signals having substantially half said frequency and having a phase difference therebetween of substantially π/2 radians.    
   
   
       15 . The communication device of  claim 14 , wherein said quadrature oscillator further includes two slave oscillators having input nodes coupled to output nodes of said source oscillator.  
   
   
       16 . The communication device of  claim 14 , wherein said communication device is a mobile station.  
   
   
       17 . A communication system comprising: 
 a first communication device; and    a second communication device able to communicate with said first communication device via a communication channel,    wherein at least one of said first communication device and said second communication device comprises: 
 a quadrature oscillator including at least a source oscillator able to oscillate at a frequency and to produce substantially anti-phase output signals at said frequency, said quadrature oscillator able to generate quadrature signals from said output signals, said quadrature signals having substantially half said frequency and having a phase difference therebetween of substantially π/2 radians.  
   
   
   
       18 . The communication system of  claim 17 , wherein said quadrature oscillator further includes two slave oscillators having input nodes coupled to output nodes of said source oscillator.  
   
   
       19 . The communication system of  claim 18 , wherein said quadrature oscillator further comprises a matching network coupling said slave oscillators to said source oscillator.