Antenna structures and methods thereof for adjusting an operating frequency range of an antenna

Abstract

A system that incorporates the subject disclosure may include, for example, a circuit for obtaining a desired bandwidth of operation of the antenna structure, adjusting a bandwidth of the antenna to achieve the desired bandwidth of operation of the antenna structure, and tuning the antenna to a new resonant frequency to accommodate transmitting or receiving RF signals at a desired band of operation. The antenna at the new resonant frequency is at least approximately at the desired bandwidth of operation of the antenna structure. Other embodiments are disclosed.

What is claimed is: 
     
         1 . A method, comprising:
 determining whether intraband carrier aggregation is desired;   adjusting, by a circuit comprising a processor, a reactive element of an antenna to reduce an operating bandwidth of the antenna responsive to a first determination that intraband carrier aggregation is not desired;   adjusting, by the circuit, the reactive element of the antenna to increase the operating bandwidth of the antenna responsive to a second determination that intraband carrier aggregation is desired; and   tuning, by the circuit, the antenna to a new resonant frequency to accommodate transmitting or receiving RF signals at a desired band of operation, wherein the antenna at the new resonant frequency has the reduced operating bandwidth or the increased operating bandwidth of the antenna.   
     
     
         2 . The method of  claim 1 , wherein the operating bandwidth is reduced responsive to the first determination to reduce harmonics. 
     
     
         3 . The method of  claim 2 , wherein the harmonics are reduced due to mixing when signals are being transmitted by the antenna. 
     
     
         4 . The method of  claim 1 , wherein the operating bandwidth is reduced responsive to the first determination to reduce intermodulation distortion. 
     
     
         5 . The method of  claim 4 , wherein the intermodulation distortion is reduced due to mixing when signals are being transmitted by the antenna. 
     
     
         6 . The method of  claim 1 , wherein the operating bandwidth of the antenna is reduced when signals are being transmitted by the antenna to reduce spurious radiation outside a desired channel. 
     
     
         7 . The method of  claim 1 , wherein the reactive element comprises one of a tunable capacitor, a tunable inductor, or a combination thereof. 
     
     
         8 . The method of  claim 1 , further comprising detecting a frequency offset in an operating frequency of the antenna, wherein the tuning of the antenna is responsive to detecting the frequency offset. 
     
     
         9 . The method of  claim 8 , further comprising determining a magnitude difference between a first signal supplied to the antenna and a second signal radiated by the antenna, wherein the frequency offset is detected according to the magnitude difference. 
     
     
         10 . The method of  claim 8 , further comprising determining a phase difference between a first signal supplied to the antenna and a second signal radiated by the antenna, wherein the frequency offset is detected according to the phase difference. 
     
     
         11 . The method of  claim 8 , further comprising measuring a change in reactance of the antenna, wherein the frequency offset is detected according to the change in reactance of the antenna. 
     
     
         12 . A method, comprising:
 responsive to a first determination that carrier aggregation is not desired, adjusting, by a circuit comprising a processor and an antenna, a quality factor of the antenna to reduce an operating bandwidth of the antenna and to reduce spurious radiation due to transmission outside a passband of the antenna; and   tuning, by the circuit, the antenna to a new resonant frequency to accommodate transmitting or receiving RF signals at a desired band of operation, wherein the antenna at the new resonant frequency has the reduced operating bandwidth of the antenna.   
     
     
         13 . The method of  claim 12 , further comprising:
 looking up LRC model parameters from a table for the antenna; and   adjusting a reactive element of the antenna according to the LRC model parameters.   
     
     
         14 . The method of  claim 13 , wherein the reactive element comprises one of a tunable capacitor, a tunable inductor, or a combination thereof. 
     
     
         15 . The method of  claim 13 , wherein the looking up is based on the first determination. 
     
     
         16 . The method of  claim 12 , further comprising detecting a frequency offset in an operating frequency of the antenna, wherein the tuning of the antenna is responsive to detecting the frequency offset. 
     
     
         17 . The method of  claim 16 , further comprising determining one of a magnitude difference between a first signal supplied to the antenna and a second signal radiated by the antenna, a phase difference between the first signal supplied to the antenna and the second signal radiated by the antenna, a change in reactance of the antenna, or any combination thereof. 
     
     
         18 . A communication device, comprising:
 an antenna structure; and   a circuit coupled to the antenna structure, wherein the circuit performs operations comprising:   responsive to a determination that interband aggregation is not desired, narrowing of a bandwidth of the antenna structure to achieve a desired bandwidth of operation of the antenna structure to reduce harmonic distortion; and   tuning the antenna structure to a new resonant frequency to accommodate transmitting or receiving RF signals at a desired band of operation, wherein the antenna structure at the new resonant frequency is at least approximately at the desired bandwidth of operation of the antenna structure.   
     
     
         19 . The communication device of  claim 18 , wherein the narrowing further comprises obtaining a reactive parameter from a look-up table to achieve the desired bandwidth of operation of the antenna structure. 
     
     
         20 . The communication device of  claim 19 , wherein the narrowing further comprises adjusting a reactive element of the antenna structure according to the reactive parameter to achieve the desired bandwidth of operation of the antenna structure.