Balanced-type mixer having circuit board

A balanced-type mixer comprising:

• a circuit board with first and second conductor patterns thereon, said circuit board being sandwiched between two pairs of dielectric strips, each pair of dielectric strips comprising a first and a second dielectric strip and being disposed between two substantially parallel conductor planes,
• said conductor planes and said first and second pairs of dielectric strips forming first and second dielectric lines, respectively, and said conductor planes forming first and second suspended lines with said first and second conductor patterns on said circuit board,
• wherein the first conductor pattern is arranged in a direction intersecting with the first dielectric strip, and first and second filter circuits for cutting off a signal which propagates through the first suspended line are provided at at least two places in the first conductor pattern which are on opposite sides of the first dielectric strip in such a manner as to be coupled to the first dielectric line, thus forming a first resonance circuit,
• two diodes are mounted in series with respect to the first conductor pattern within the first resonance circuit, and
• the second conductor pattern is extended from said first conductor pattern at substantially the midpoint between the first and second filter circuits in a direction along the length of the first dielectric strip, and a third filter circuit is provided in this second conductor pattern, whereby the second conductor patter forms a second resonance circuit between the first conductor pattern and the third filter circuit, the second dielectric line being disposed at a position which intersects with this second resonance circuit,
• whereby said balanced-type mixer is adapted for propagating an RF signal and a Lo signal through the first and second dielectric lines, respectively.