Patent Publication Number: US-7898361-B2

Title: Antenna feed copling structure of a duplexer

Description:
This Application Claims the Priority Benefit of Taiwan Patent Application Number 097204485 filed on Mar. 14, 2008. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an antenna duplexer and more particularly, to an antenna feed coupling structure of a duplexer, which allows adjustment of the depth in which two feed-in adjustment rods and two coupling structure adjustment rods enter a resonance cavity and a feed-in cavity, achieving accurate resonance frequency and proper coupling structure amount for smooth operation of signal at both the transmitter side and the receiver side. The antenna feed coupling structure eliminates any soldering techniques, saving the manufacturing cost and facilitating small-size design. 
     2. Description of the Related Art 
       FIG. 5  illustrates an antenna feed coupling structure of a duplexer according to the prior art. According to this design, the antenna feed coupling structure comprises a hollow base A that defines therein a resonance cavity A 1 , a plurality of upright resonators A 2  arranged in the resonance cavity A 1 , two output port A 3  respectively connected to one upright resonator A 2  at each of two distal ends of the resonance cavity A 1  and extended out of one side of the base A, a signal input port A 4  cut through the bottom wall of the base A and disposed at one side relative to the resonance cavity A 1 , a groove A 5  extended from a middle part of the resonance cavity A 1  toward the signal input port A 4 , a first feed line A 6  connected between two upright resonators A 2  are disposed in the resonance cavity A 1  at two opposite sides relative to the groove A 5 , a second feed line A 7  perpendicularly extended from the first feed line A 6  through the groove A 5  into the signal input port A 4 , and a cover B covering the hollow base A. 
     When wishing to adjust the magnetic coupling structure amount among the upright resonators A 2 , change the length of first feed line A 6  at each of two sides relative to the second feed line A 7  and the length of the second feed line A 7 , and therefore the resonance frequency, feed-in amount and equivalent length are relatively adjusted. However, when changing the length of the first feed line A 6  and the second feed line A 7 , the distance between the two associating upright resonators A 2  as well as the length and location of the groove A 5  must be relatively changed. When extending the distance between the two associating upright resonators and the length the groove, the size of the antenna feed coupling structure will be relatively increased. 
     Further, when making duplexers for different frequency bands to satisfy different clients, different sizes of antenna feed coupling structures must be prepared. In consequence, the antenna feed coupling structure manufacturing cost will be relatively increased. Following market development trend toward light, thin, short and small characteristics, the aforesaid prior art design cannot meet market requirements. 
     Therefore, it is desirable to provide an antenna feed coupling structure for duplexer that eliminates the aforesaid drawbacks. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide an antenna feed coupling structure for duplexer, which has small-size and low manufacturing cost characteristics. It is another object of the present invention to provide an antenna feed coupling structure for duplexer, which allows easy adjustment of the feed-in amount and coupling structure amount without any soldering techniques. 
     To achieve these and other objects of the present invention, an antenna feed coupling structure of a duplexer includes a base defining a detoured resonance cavity and a T-shaped feed-in cavity perpendicularly intersecting the resonance cavity and a signal input port in connection with the head of the feed-in cavity, a cover closing the base, and adjustment rods mounted in the base and suspending in the resonance cavity and the feed-in cavity. The adjustment rods include two feed-in adjustment rods and two coupling structure adjustment rods suspending in the intersected area between the resonance cavity and the feed-in cavity and respectively kept in horizontal and in vertical relative to the resonance cavity and rotatable inwards and outwards to adjust the feed-in amount and coupling structure amount of the antenna feed coupling structure respectively. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an oblique elevation of an antenna feed coupling structure in accordance with the present invention. 
         FIG. 2  is an exploded view of the antenna feed coupling structure in accordance with the present invention. 
         FIG. 3  corresponds to  FIG. 2 , showing the cover turned upside down. 
         FIG. 4  is a schematic perspective view of the antenna feed coupling structure in accordance with the present invention. 
         FIG. 5  is a schematic perspective view of an antenna feed coupling structure according to the prior art. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1˜4 , an antenna feed coupling structure of a duplexer in accordance with the present invention is shown comprising a base  1  and a cover  2 . 
     The base  1  comprises a detoured resonance cavity  10 , a plurality of upright resonators  11  arranged in the resonance cavity  10 , a plurality of, for example, two output port  12  disposed near two distal ends of one side thereof, a plurality of, for example, two metal conductors  111  that connect one respective resonator  11  at each of two distal ends of the resonance cavity  10  to the output port  12  respectively, a T-shaped feed-in cavity  13  perpendicularly intersecting the resonance cavity  10 , and a signal input port  14  extended from one end of the T-shaped feed-in cavity  13  remote from the resonance cavity  10  and cut through the bottom wall of the base  1 . 
     The cover  2  comprises a plurality of through holes  21  corresponding to the upright resonators  11 , and a plurality of adjustment rods  22  respectively and vertically adjustably mounted in the through holes  21 . The adjustment rods  22  include two feed-in adjustment rods  221  and two coupling structure adjustment rods  222  respectively mounted in the four through holes  21  in the intersected area between the resonance cavity  10  and the feed-in cavity  13  and arranged at right angles. 
     Referring to  FIGS. 1˜4  again, during the use of the antenna feed coupling structure, incident signal is fed through the T-shaped feed-in cavity  13  into the resonance cavity  10 , causing the upright resonators  11  to exhibits resonance. The resonated signal thus produced is outputted through the output port  12 . As stated above, the two feed-in adjustment rods  221  and the two coupling structure adjustment rods  222  are disposed in the intersected area between the resonance cavity  10  and the feed-in cavity  13 . The two feed-in adjustment rods  221  are disposed at two sides of the feed-in cavity  13  within the resonance cavity  10  and kept in horizontal relative to the resonance cavity  10 . The two coupling structure adjustment rods  222  are disposed in the feed-in cavity  13  within the resonance cavity  10  and kept in vertical relative to the resonance cavity  10  and aimed at the signal input port  14  in the feed-in cavity  13 . 
     The adjustment rods  22 , including the feed-in adjustment rods  221  and the coupling structure adjustment rods  222 , can be screw nails, screw rods, or any other rod members that facilitate adjustment of the position upwards and downwards. When adjusting the two feed-in adjustment rods  221  toward or apart from the bottom side of the resonance cavity  10 , the feed-in amount is relatively adjusted. When adjusting the depth in which the two coupling structure adjustment rods  222  enter the resonance cavity  10 , the coupling structure amount is relatively adjusted. During a wireless signal transmission, noises usually will be produced. By means of rotating the feed-in adjustment rods  221  and the coupling structure adjustment rods  222  to adjust the feed-in amount and the coupling structure amount, noises are removed from the input signal, assuring high sharpness of signal and avoiding signal distortion. 
     Further, a user can directly adjust the depth of the feed-in adjustment rods  221  and the coupling structure adjustment rods  222  in the resonance cavity  10  without detaching the cover  2  from the base  1 , and therefore the antenna feed coupling structure is convenient to use. Further, because one single manufacturing tool system is necessary for making antenna feed coupling structures to fit different requirements from different users or clients, saving much the tooling cost and inventory management cost. 
     Further, the dimension of the feed-in cavity  13  may be changed. When the dimension of the feed-in cavity  13  is reduced, the depth in which the feed-in adjustment rods  221  and the coupling structure adjustment rods  222  enter the resonance cavity  10  is relatively increased, achieving the expected effects. Therefore, the invention allows the feed-in cavity  13  to be small-sized so that the whole dimension of the antenna feed coupling structure can be greatly reduced, providing light, thin, short and small characteristics. Further, the invention eliminates any soldering techniques, saving the manufacturing cost. 
     In conclusion, the invention provides an antenna feed coupling structure, which has the following advantages and features: 
     1. The feed-in adjustment rods  221  and the coupling structure adjustment rods  222  are mounted in the cover  2  and suspending in the intersected area between the feed-in cavity  13  and the resonance cavity  10 , wherein the feed-in adjustment rods  221  are respectively disposed at two opposite lateral sides of the feed-in cavity  13  within the resonance cavity  10  and adjustable to change the feed-in amount; the coupling structure adjustment rods  222  are kept in vertical relative to the resonance cavity  10  and adjustable to change the coupling structure amount. Therefore, the antenna feed coupling structure can be adjusted to fit different requirements from different users. 
     2. The feed-in cavity  13  can be made having a T-shaped or profile. Further, the feed-in cavity  13  intersects the resonance cavity  10  in a perpendicular manner. If the dimension of the feed-in cavity  13  is made relatively smaller, the feed-in adjustment rods  221  and the coupling structure adjustment rods  222  are adjusted to enter the resonance cavity and the feed-in cavity  13  relatively deeper, achieving the same coupling structure effect. Therefore, the antenna feed coupling structure of the present invention can be made having light, thin, and short. 
     A prototype of antenna feed coupling structure has been constructed with the features of  FIGS. 1-4 . The antenna feed coupling structure functions smoothly to provide all of the features disclosed earlier. 
     Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.