Electronic apparatus and design method

Abstract

The invention realizes a wireless communication module that is capable of transmitting the fundamental wave with low loss and reducing the double higher harmonic wave level to a desired level or lower as the whole module. The invention provides a front end module to be used for a wireless communication system such as cellular phone in which at least an output power amplifier, a matching circuit, and a low-pass filter are mounted on one insulating substrate and these circuits are connected in the above-mentioned order, wherein the relative phase of the double higher harmonic wave impedance between phases in view of the matching circuit side and the low-pass filter side from the connection point between the matching circuit and the low-pass filter is set in a range of 180 degrees ±90 degrees.

1 . An electronic apparatus to be used for a wireless communication system in which at least an output power amplifier, a matching circuit, and a low-pass filter are mounted on one insulating substrate and connected in this order, wherein the phase of the double higher harmonic wave impedance in view of the low-pass filter side from the connection point between the matching circuit and the low-pass filter is set in a range of 180 degrees ±90 degrees with respect to the phase of the double higher harmonic wave impedance in view of the matching circuit from the connection point.  
   
   
       2 . The electronic apparatus according to  claim 1 , wherein the low-pass filter comprises a resonance circuit having a capacitance element and an inductance element connected in parallel and a capacitance element connected between the output point of the resonance circuit and a constant potential point.  
   
   
       3 . The electronic apparatus according to  claim 2 , wherein the matching circuit is structured including a resonance circuit comprising a capacitance element and inductance element connected in parallel.  
   
   
       4 . The electronic apparatus according to  claim 3 , wherein a transmission/reception switching circuit for switching the signal between a transmission signal and a received signal is additionally mounted on the insulating substrate.  
   
   
       5 . The electronic apparatus according to  claim 1 , wherein a set of the output power amplifier, a matching circuit, and a low-pass filter is provided correspondingly to each frequency band of two or more frequency bands, and the double higher harmonic wave of any one of the frequency bands is in any one of other frequency bands.  
   
   
       6 . The electronic apparatus according to  claim 5 , wherein a branching circuit for branching a received signal into the two or more frequency bands is additionally mounted on the insulating substrate.  
   
   
       7 . An electronic apparatus used for a wireless communication system that communicates by use of two or more frequency bands, 
 wherein at least a set of an output power amplifier, a matching circuit, and a low-pass filter is provided correspondingly to each frequency band, the sets are mounted on one insulating substrate, and the output power amplifier, the matching circuit, and the low-pass filter of each set are connected in this order, and    wherein the phase of the double higher harmonic wave impedance in view of the low-pass filter side from the connection point between the matching circuit and the low-pass filter is deviated from the phase matching position by means of the low-pass filter.    
   
   
       8 . The electronic apparatus according to  claim 7 , wherein the low-pass filter comprises a resonance circuit having a capacitance element and an inductance element connected in parallel and a capacitance element connected between the output point of the resonance circuit and a constant potential point.  
   
   
       9 . The electronic apparatus according to  claim 8 , wherein the matching circuit is structured including a resonance circuit comprising a capacitance element and inductance element connected in parallel.  
   
   
       10 . The electronic apparatus according to  claim 9 , wherein a transmission/reception switching circuit for switching the signal between a transmission signal and a received signal is additionally mounted on the insulating substrate.  
   
   
       11 . The electronic apparatus according to  claim 10 , wherein a branching circuit for branching a received signal into a plurality of frequency bands is additionally mounted on the insulating substrate.  
   
   
       12 - 15 . (canceled)  
   
   
       16 . A design method for designing an electronic apparatus in which at least an output power amplifier, a matching circuit, and a low-pass filter are mounted on one insulating substrate and connected in this order, 
 wherein the phase of the double higher harmonic wave impedance in view of the low-pass filter side from the connection point between the matching circuit and the low-pass filter is set in a range of 180 degrees ±X (X ranges within 90 degrees) with respect to the phase of the double higher harmonic wave impedance in view of the matching circuit from the connection point, and    wherein the X is determined based on the standard value to which a predetermined margin is added.    
   
   
       17 . The design method for designing an electronic apparatus according to  claim 16 , wherein the X is 90 degrees in the case that the margin is approximately 10% of the standard value.  
   
   
       18 . The design method for designing an electronic apparatus according to  claim 16 , wherein the X is 45 degrees in the case that the margin is approximately 25% of the standard value.