Tunable microwave bandstop resonant cavity apparatus

Claim 2

Rectangular microwave resonant cavity apparatus having one closed end and being adapted at the other end for electromagnetic coupling to a rectangular waveguide wherein the improvement comprises first and second conductive members adapted for adjustable penetration of said cavity, each of said conductive members being positioned to substantially affect both the resonant frequency and quality factor of said cavity.

Claim 3

The apparatus defined in claim 1 wherein said first member is positioned to penetrate said cavity in the region of said closed end, and said second member is positioned to penetrate said cavity in the region of said end adapted for coupling, such that increased penetration of said first member effects a decrease in resonant frequency with an attendant decrease in quality factor, and increased penetration of said second member effects a decrease in resonant frequency with an attendant increase in quality factor.

Claim 4

The apparatus defined in claim 2 furtHer comprising a third conductive member adapted for adjustable penetration of said cavity from a direction opposite the direction of penetration of said second member, said third member positioned in the region of said end adapted for coupling to substantially affect both the resonant frequency and the quality factor of said cavity.

Claim 5

The apparatus defined in claim 1 wherein said members are positioned to penetrate said cavity from opposite directions, said members located in the region of said end adapted for coupling.

Claim 6

Microwave bandstop filter apparatus for attenuating microwave energy in a rectangular waveguide comprising: a rectangular waveguide section having a longitudinal axis perpendicular to the longitudinal axis of said rectangular waveguide, said waveguide section having one closed end and an inductive coupling to said rectangular waveguide at the other end; a first tuning screw positioned to affect both resonant frequency and quality factor, protruding into said waveguide section transverse to said longitudinal axis of said section in the half of said section nearest said closed end; and second and third tuning screws, oppositely disposed, positioned to affect both resonant frequency and quality factor, protruding into said waveguide section transverse to said longitudinal axis of said section in the half of said section nearest said inductive coupling, said tuning screws located such that increased penetration of said first tuning screws effects a decrease in the resonant frequency of said cavity with an attendant decrease in quality factor, and increased penetration of said second and third tuning screws effects a decrease in said resonant frequency with an attendant increase in said quality factor.

Claim 7

Microwave bandstop filter apparatus for attenuating microwave energy in a rectangular waveguide comprising: a rectangular waveguide section having a longitudinal axis perpendicular to the longitudinal axis of said rectangular waveguide, said waveguide section having one closed end and an inductive coupling to said rectangular waveguide at the other end; a first tuning screw positioned to affect both resonant frequency and quality factor, protruding into said waveguide section transverse to said longitudinal axis of said section in the half of said section nearest said closed end; and second and third tuning screws, oppositely disposed, positioned to affect both resonant frequency and quality factor, protruding into said waveguide section transverse to said longitudinal axis of said section in the half of said section nearest said inductive coupling, said tuning screws located such that increased penetration of said first tuning screws effects a decrease in the resonant frequency of said cavity with an attendant decrease in quality factor, and increased penetration of said second and third tuning screws effects a decrease in said resonant frequency with an attendant increase in said quality factor.

Claim 8

The apparatus defined in claim 5 wherein said first, second, and third tuning screws are in the plane defined by the longitudinal axes of said waveguide and said waveguide section.

Claim 9

Microwave bandstop filter apparatus for attenuating microwave energy propagating along the longitudinal axis of a rectangular waveguide, the attenuated energy having a characteristic guide wavelength, comprising: a rectangular waveguide cavity having substantially the same cross-sectional dimensions as said rectangular waveguide, said cavity having a longitudinal axis perpendicular to said longitudinal axis of said rectangular waveguide, said cavity being closed at one end and having an inductive coupling to said rectangular waveguide at the other end, the length of said cavity being substantially equal to one half of said characteristic wavelength; a first tuning screw positioned to affect both resonant frequency and quality factor, protruding into said cavity transverse to said longitudinal axis of said cavity at a distance from said closed end substantially equal to one eighth of said characteristic wavelength; and second and third tuning screws oppositely disposed, positioned to affect both resonant frequency and quality factor, protruding into said cavity transverse to said longitudinal axis of said cavity at a distance from said inductive coupling substantially equal to one eighth of said characteristic guide wavelength.

Claim 10

Microwave bandstop filter apparatus for attenuating microwave energy propagating along the longitudinal axis of a rectangular waveguide, the attenuated energy having a characteristic guide wavelength, comprising: a rectangular waveguide cavity having substantially the same cross-sectional dimensions as said rectangular waveguide, said cavity having a longitudinal axis perpendicular to said longitudinal axis of said rectangular waveguide, said cavity being closed at one end and having an inductive coupling to said rectangular waveguide at the other end, the length of said cavity being substantially equal to one half of said characteristic wavelength; a first tuning screw positioned to affect both resonant frequency and quality factor, protruding into said cavity transverse to said longitudinal axis of said cavity at a distance from said closed end substantially equal to one eighth of said characteristic wavelength; and second and third tuning screws oppositely disposed, positioned to affect both resonant frequency and quality factor, protruding into said cavity transverse to said longitudinal axis of said cavity at a distance from said inductive coupling substantially equal to one eighth of said characteristic guide wavelength.

Claim 11

The apparatus defined in claim 7 wherein said first, second, and third tuning screws are in the plane defined by the longitudinal axes of said waveguide and said waveguide section.

Claim 12

Microwave bandstop filter apparatus for attenuating microwave energy propagating along the longitudinal axis of a rectangular waveguide, said attenuated energy having a characteristic wavelength, comprising: a rectangular waveguide section having a longitudinal axis perpendicular to said longitudinal axis of said rectangular waveguide and approximately one half of said characteristic wavelength in length, said waveguide section having one closed end and an inductive coupling to said rectangular waveguide at the other end; tuning means positioned to affect both resonant frequency and quality factor, protruding into Said waveguide section transverse to said longitudinal axis of said section at a distance from said closed end substantially equal to one eighth of said characteristic wavelength; and a pair of tuning means, oppositely disposed, positioned to affect both resonant frequency and quality factor, protruding into said waveguide section transverse to said longitudinal axis of said section at a distance from said inductive coupling substantially equal to one eighth of said characteristic wavelength.

Claim 13

Microwave bandstop filter apparatus for attenuating microwave energy propagating along the longitudinal axis of a rectangular waveguide, said attenuated energy having a characteristic wavelength, comprising: a rectangular waveguide section having a longitudinal axis perpendicular to said longitudinal axis of said rectangular waveguide and approximately one half of said characteristic wavelength in length, said waveguide section having one closed end and an inductive coupling to said rectangular waveguide at the other end; tuning means positioned to affect both resonant frequency and quality factor, protruding into Said waveguide section transverse to said longitudinal axis of said section at a distance from said closed end substantially equal to one eighth of said characteristic wavelength; and a pair of tuning means, oppositely disposed, positioned to affect both resonant frequency and quality factor, protruding into said waveguide section transverse to said longitudinal axis of said section at a distance from said inductive coupling substantially equal to one eighth of said characteristic wavelength.

Claim 14

The apparatus defined in claim 9 wherein said first, second, and third tuning means are respectively first, second, and third tuning screws threadably mounted through the walls of said cavity.

Claim 15

Microwave bandstop filter apparatus for attenuating microwave energy propagating along the longitudinal axis of a rectangular waveguide, said attenuated energy having a characteristic wavelength, comprising: a rectangular waveguide section, having a longitudinal axis perpendicular to said longitudinal axis of said rectangular waveguide, approximately one-half of said characteristic wavelength in length, said waveguide section having one closed end and an inductive coupling to said rectangular waveguide at the other end; first tuning means, positioned to affect both resonant frequency and quality factor, protruding into said waveguide section transverse to said longitudinal axis of said waveguide section at a distance from said closed end substantially equal to one-eighth of said characteristic wavelength; and second tuning means positioned to affect both resonant frequency and quality factor, protruding into said waveguide section transverse to said longitudinal axis of said waveguide section at a distance from said inductive coupling substantially equal to one-eighth of said characteristic guide wavelength.

Claim 16

Microwave bandstop filter apparatus for attenuating microwave energy propagating along the longitudinal axis of a rectangular waveguide, said attenuated energy having a characteristic wavelength, comprising: a rectangular waveguide section, having a longitudinal axis perpendicular to said longitudinal axis of said rectangular waveguide, approximately one-half of said characteristic wavelength in length, said waveguide section having one closed end and an inductive coupling to said rectangular waveguide at the other end; first tuning means, positioned to affect both resonant frequency and quality factor, protruding into said waveguide section transverse to said longitudinal axis of said waveguide section at a distance from said closed end substantially equal to one-eighth of said characteristic wavelength; and second tuning means positioned to affect both resonant frequency and quality factor, protruding into said waveguide section transverse to said longitudinal axis of said waveguide section at a distance from said inductive coupling substantially equal to one-eighth of said characteristic guide wavelength.

Claim 17

The apparatus defined in claim 11 wherein said first and second tuning means penetrate the same wall of said rectangular waveguide section.