Radio frequency signal coupler

Claim 1

Apparatus for coupling a source of a radio frequency (RF) signal to an RF signal processing circuit, comprising: an electrically insulating body portion; first and second input coupling means formed on said body portion for coupling to said source; first and second output coupling means formed on said body portion for coupling to said RF signal processing circuit; a first conductor formed on said body portion and coupled between said first input coupling means and said first output coupling means; a second conductor formed on said body portion and coupled between said second input coupling means and said second output coupling means; resonant circuit means formed on said body portion and coupled between said first and second conductors for providing a series resonant circuit therebetween; said resonant circuit means including inductance means formed on said body portion for providing series inductance and capacitance means formed on said body portion for providing series capacitance; said resonant circuit means including a third conductor having a meander portion for forming said inductance means and a gap portion for forming said capacitance means; wherein said first, second, and third conductors are formed in a first plane as substantially flat strips on said body portion; said third conductor includes first and second plate portions defining said gap therebetween; and said body portion includes a tab portion having first and second faces located in respective second and third parallel planes, said second and third planes being substantially perpendicular to said first plane and having a separation therebetween substantially equal to said gap, said first and second plate portions of said third conductor being formed on respective ones of said second and third planes.