Abstract: A hybrid ring mixer includes an annular conducting ring on a gallium arsenide substrate coated on the bottom with a conducting layer to comprise a strip transmission line. Three conductors spaced by 120.degree. extend radially outward from the annular ring to define local oscillator, signal input and i-f ports, respectively. A pair of conductors spaced by substantially 120.degree. extend radially inward to comprise diode ports. A conducting surface inside the annular ring is grounded and has circular sectors of different radius bounded by radii extending from the center of the ring and bisecting the signal and local oscillator ports, respectively. The sector of larger radius is located in the 120.degree. sector between the signal and local oscillator ports. Mesa diodes are connected between each of the diode ports and the sector of smaller radius.