| 摘要 |
PROBLEM TO BE SOLVED: To effectively display an amplitude probability distribution(APD) by using an area recognition display method based on a group of bands having a plurality of gradations such as respectively different color bands. SOLUTION: In a front end 201, a radio frequency input RF is converted into an intermediate frequency signal IF on the basis of a predetermined sweep command fed from an operation unit 211 to a local oscillator control circuit via a control unit 210, and then, the intermediate frequency signal IF is outputted. From the control circuit, a front end state number (i) corresponding to the sweep command or a trigger signal is outputted to a computing unit 208. The front end 201 is a down converter converting a received frequency signal of fRF into an intermediate frequency signal of fIF. A histogram measurement circuit 206 is constructed of a switch switching a histogram measuring state and a measurement result outputting state mutually, an adder, a register, a RAM 207, and an interface circuit. The RAM 207 outputs data designated by an address input m(k) in a starting edge of a clock to an 0 port so as to hold it until the following starting edge of the clock. |
