Abstract: A vehicle mounted DSRC apparatus is capable of achieving reduction in the size and cost thereof. The vehicle mounted DSRC apparatus includes an ASK data generation part 11, an I data generation part 21, a Q data generation part 22, a first band limiting filter 23A for band limiting I data and ASK data, a second band limiting filter 24 for band limiting Q data, an ASK low pass filter 12A for removing harmonic components from the ASK data, first and second low pass filters 25, 26 for removing harmonic components from QPSK data, an ASK modulator 13 for ASK modulating the ASK data, a QPSK modulator 27 for QPSK modulating the QPSK data, and a power amplifier 30 for amplifying output data of the ASK modulator 13 or the QPSK modulator 27 to a desired level thereby to output it to an antenna as an ASK modulated signal and a QPSK modulated signal.

Abstract: An infrared imaging device includes an infrared detector element having a pin structure which detects infrared rays 8 to 12 microns in wavelength. The pin structure comprises a multi-quantum well structure as an intrinsic layer including a plurality of Al.sub.y Ga.sub.1-y As quantum well layers sandwiched by respective Al.sub.x Ga.sub.1-x As quantum barrier layers (x>y) and a p type Al.sub.x Ga.sub.1-x As layer and an n type Al.sub.x Ga.sub.1-x As layer sandwiching the intrinsic layer. An infrared imaging device includes a plurality of picture units, each picture unit including an infrared detector element and a corresponding GaAs FET having a source region connected with the n layer of the infrared detector element on the same substrate. The picture unit and corresponding FET may be monolithically integrated on the same substrate with an n type channel in the substrate interconnecting the picture unit and the corresponding FET.