Nonradiative dielectric waveguide and a millimeter-wave transmitting/receiving apparatus

Abstract

A NRD guide includes a pair of parallel plate conductors opposed to each other at a spacing equal to or shorter than half the wavelength of a high-frequency signal to be transmitted and having opposing inner surfaces whose arithmetic average roughness Ra satisfies 0.1 μm≦Ra≦50 μm, and a dielectric strip arranged between the pair of parallel plate conductors and held in contact with the respective inner surfaces of the parallel plate conductors. The dielectric strip is strongly secured to the inner surfaces to exhibit an excellent durability. The transmission loss of the high-frequency signal can be effectively suppressed.

1 - 21 . (canceled)  
   
   
       22 . A millimeter wave transmitting/receiving apparatus, comprising: 
 a pair of parallel plate conductors opposed to each other at a spacing equal to or shorter than half the wavelength of a high-frequency signal to be transmitted;    a circulator made of two ferromagnetic plates provided between the pair of parallel plate conductors and opposed to each other in the same direction as the pair of parallel plate conductors being spaced apart;    a first dielectric strip arranged between the pair of parallel plate conductors;    a millimeter wave signal oscillator provided at one end of the first dielectric strip for outputting a millimeter wave signal to be transmitted;    a second dielectric strip connected with the one end of the first dielectric strip and radially arranged with respect to the circulator between the pair of parallel plate conductors;    a third dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors and having a transmitting/receiving antenna at its leading end;    a fourth dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    first, second, third and fourth suppressors arranged between the one end of the first dielectric strip and the millimeter wave signal oscillator and between the second, third and fourth dielectric strips and the circulator, and formed by arranging a plurality of conductive layers at specified intervals in a plane parallel to a transmission direction of a high-frequency signal inside the ends of the respective dielectric strips; and    a mixer for mixing part of the millimeter wave signal outputted from the millimeter wave signal oscillator and a radio wave received by the transmitting/receiving antenna to generate an intermediate-frequency signal by coupling an intermediate position of the first dielectric strip and that of the fourth dielectric strip to each other.    
   
   
       23 . A millimeter wave transmitting/receiving apparatus according to  claim 22 , wherein a dimension of each conductive layer along the transmission direction is equal to or shorter than half the wavelength of a TEM mode electromagnetic wave of the high-frequency signal, and a thickness thereof is 0.1 mm or smaller.  
   
   
       24 . A millimeter wave transmitting/receiving apparatus, comprising: 
 a pair of parallel plate conductors opposed to each other at a spacing equal to or shorter than half the wavelength of a high-frequency signal to be transmitted;    a circulator made of two ferromagnetic plates provided between the pair of parallel plate conductors and opposed to each other in the same direction as the pair of parallel plate conductors being spaced apart;    a first dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    a millimeter wave signal oscillator provided at one end of the first dielectric strip for outputting a millimeter wave signal to be transmitted;    a second dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors and having a transmitting antenna at its leading end;    a third dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    first, second, third and fourth suppressors arranged between one end of the first dielectric strip and the millimeter wave signal oscillator and between the first, second and third dielectric strips and the circulator, and formed by arranging a plurality of conductive layers at specified intervals in a plane parallel to a transmission direction of a high-frequency signal inside the ends of the respective dielectric strips;    a fourth dielectric strip having one end connected with the first or second dielectric strip between the pair of parallel plate conductors for transmitting part of the millimeter wave signal outputted from the millimeter wave signal oscillator;    a fifth dielectric strip arranged between the pair of parallel plate conductors and having a receiving antenna at its leading end; and    a mixer for mixing part of the millimeter wave signal outputted from the millimeter wave signal oscillator and a radio wave received by the receiving antenna to generate an intermediate-frequency signal by coupling an intermediate position of the fourth dielectric strip and that of the fifth dielectric strip to each other.    
   
   
       25 . A millimeter wave transmitting/receiving apparatus according to  claim 24 , wherein a dimension of each conductive layer along the transmission direction is equal to or shorter than half the wavelength of a TEM mode electromagnetic wave of the high-frequency signal, and a thickness thereof is 0.1 mm or smaller.  
   
   
       26 . A millimeter wave transmitting/receiving apparatus, comprising: 
 a pair of parallel plate conductors opposed to each other at a spacing equal to or shorter than half the wavelength of a millimeter wave signal to be transmitted;    a circulator made of two ferromagnetic plates provided between the pair of parallel plate conductors and opposed to each other in the same direction as the pair of parallel plate conductors being spaced apart;    a first dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    a millimeter wave signal oscillator provided at one end of the second dielectric strip for outputting the millimeter wave signal to be transmitted;    a second dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors, and having a transmitting/receiving antenna at it leading end;    a third dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    a fourth dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors, and having one end connected with the first dielectric strip;    first, second and third suppressors arranged between the first, second and third dielectric strips and the circulator for suppressing electromagnetic waves of unnecessary modes;    first, second and third impedance matching members arranged at the end faces of the first, second and third suppressors toward the circulator and having a relative dielectric constant different from that of the first, second and third dielectric strips; and    a mixer for mixing part of the millimeter wave signal outputted from the millimeter wave signal oscillator and having transmitted in the fourth dielectric strip and a radio wave received by the transmitting/receiving antenna to generate an intermediate-frequency signal and transmitted in the third dielectric strip by coupling an intermediate position of the third dielectric strip and that of the fourth dielectric strip to each other.    
   
   
       27 . A millimeter wave transmitting/receiving apparatus according to  claim 26 , wherein the impedance matching members are formed at their sides toward the respective parallel plate conductors with stepped portions having a height substantially equal to the thickness of the respective ferromagnetic plates forming the circulator, and the impedance matching members and the circulator are connected by holding the impedance matching members by the two ferromagnetic plates at the stepped portions.  
   
   
       28 . A millimeter wave transmitting/receiving apparatus, comprising: 
 a pair of parallel plate conductors opposed to each other at a spacing equal to or shorter than half the wavelength of a millimeter wave signal to be transmitted;    a circulator made of two ferromagnetic plates provided between the pair of parallel plate conductors and opposed to each other in the same direction as the pair of parallel plate conductors being spaced apart;    a first dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    a millimeter wave signal oscillator provided at one end of the first dielectric strip for outputting the millimeter wave signal to be transmitted;    a second dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors and having a transmitting antenna at its leading end;    a third dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    first, second and third suppressors arranged between the first, second, and third dielectric strips and the circulator for suppressing electromagnetic waves of unnecessary modes;    first, second and third impedance matching members arranged at the end faces of the first, second and third suppressors toward the circulator and having a relative dielectric constant different from that of the second, third and fourth dielectric strips;    a fourth dielectric strip having one end connected with the first dielectric strip between the pair of parallel plate conductors for transmitting part of the millimeter wave signal outputted from the millimeter wave signal oscillator;    a fifth dielectric strip arranged between the pair of parallel plate conductors and having a receiving antenna at its leading end; and    a mixer for mixing part of the millimeter wave signal outputted from the millimeter wave signal oscillator and a radio wave received by the receiving antenna to generate an intermediate-frequency signal by coupling an intermediate position of the fourth dielectric strip and that of the fifth dielectric strip to each other.    
   
   
       29 . A millimeter wave transmitting/receiving apparatus according to  claim 28 , wherein the impedance matching members are formed at their sides toward the respective parallel plate conductors with stepped portions having a height substantially equal to the thickness of the respective ferromagnetic plates forming the circulator, and the impedance matching members and the circulator are connected by holding the impedance matching members by the two ferromagnetic plates at the stepped portions.  
   
   
       30 . A millimeter wave transmitting/receiving apparatus, comprising: 
 a pair of parallel plate conductors opposed to each other at a spacing equal to or shorter than half the wavelength of a millimeter wave signal to be transmitted;    a circulator made of two ferromagnetic plates provided between the pair of parallel plate conductors and opposed to each other in the same direction as the pair of parallel plate conductors being spaced apart;    a first dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    a millimeter wave signal oscillator provided at one end of the first dielectric strip for outputting the millimeter wave signal to be transmitted;    a second dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    a third dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    a fourth dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    a metallic waveguide having an open termination at one end connected with an opening formed in at least one of the pair of parallel plate conductors in a position corresponding to where the electric field of a standing wave of IBM mode transmitting in the third dielectric strip is at maximum while having an open termination at the other end provided with a transmitting/receiving antenna;    a mixer for mixing part of the millimeter wave signal from the millimeter wave signal oscillator having transmitted in the fourth dielectric strip and a radio wave having transmitted in the third dielectric strip and received by the transmitting/receiving antenna to generate an intermediate-frequency signal by coupling an intermediate position of the third dielectric strip and that of the fourth dielectric strip to each other.    
   
   
       31 . A millimeter wave transmitting/receiving apparatus, comprising: 
 a pair of parallel plate conductors opposed to each other at a spacing equal to or shorter than half the wavelength of a millimeter wave signal to be transmitted;    a circulator made of two ferromagnetic plates provided between the pair of parallel plate conductors and opposed to each other in the same direction as the pair of parallel plate conductors being spaced apart;    a first dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    a millimeter wave signal oscillator provided at one end of the second dielectric strip for outputting the millimeter wave signal to be transmitted;    a second dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    a third dielectric strip radially arranged with respect to the circulator between the pair of parallel plate conductors;    a fourth dielectric strip having one end connected with the first dielectric strip between the pair of parallel plate conductors for transmitting part of the millimeter wave signal outputted from the millimeter wave signal oscillator;    a fifth dielectric strip arranged between the pair of parallel plate conductors;    a first metallic waveguide having an open termination at one end connected with an opening formed in at least one of the pair of parallel plate conductors in a position corresponding to where the electric field of a standing wave of LSM mode transmitting in the second dielectric strip is at maximum while having an open termination at the other end provided with a transmitting antenna;    a second metallic waveguide having an open termination at one end connected with an opening formed in at least one of the pair of parallel plate conductors in a position corresponding to where the electric field of a standing wave of LSM mode transmitting in the fifth dielectric strip is at maximum while having an open termination at the other end provided with a receiving antenna; and    a mixer for mixing part of the millimeter wave signal outputted from the millimeter wave signal oscillator and a radio wave received by the receiving antenna to generate an intermediate-frequency signal by coupling an intermediate position of the fourth dielectric strip and that of the fifth dielectric strip to each other.