Abstract: A mirror Fresnel lens (12) is disposed on a base (11), on which a liquid crystal display (18) is mounted. The liquid crystal display (18) is provided with a polarization plate (24) only in the mirror Fresnel lens (12) side. Light from a light source (15) passes through the liquid crystal display (18), is reflected by the mirror Fresnel lens (12), again passes through the liquid crystal display (18), is converged by a projection lens 16 and reflected by the mirror (17) and eventually arrives at a screen (20). A separated polarization plate (25) is provided in a manner to overlap with the projection lens 16. The separated polarization plate (25) is paired with the polarization plate (24).

Abstract: In an FET amplifier comprising a series connection of a coaxial-to-waveguide converter and a circulator for supplying an FET with an input signal of a wide microwave band, such as an octave band between about 1 GHz and 12 GHz, a d.c. bias voltage is applied to the FET through the circulator from a terminator therefor. For this purpose, the terminator comprises an inner and an outer conductor insulated ohmically from each other and shunted for the microwave band, as by a capacitor of several picofarads. Preferably, a resistor and a third conductor are successively connected to the inner conductor with the capacitor placed at an end of the resistor remoter from the inner conductor and with a dummy for the input signal positioned between the outer and the third conductors.