amplified to have appropriate noise characteristics and gain characteristics by if amplifier 15 condensers 17 a and 17 b and coil 18 and is output from output terminal 19 it is noted that lna 11 local oscillators 13 a and 13 b and if amplifier 15 are powered through power supply unit 16 0025 fig3 a and 3b are cross sectional views showing the configuration of two local oscillators 13 a and 13 b shown in fig2 fig3 a is a cross sectional view cut along a line iiia iiia in fig3 b while fig3 b is a cross sectional view cut along a line iiib iiib in fig3 a in fig3 a and 3b a substrate 24 with two local oscillators 13 a and 13 b mounted thereon and a conductive bar 25 are housed within one shielding chamber 20 a in a metal shielding box 20 local oscillator 13 a includes a dielectric resonator 21 a an oscillation device 22 a and a microstrip line 23 a local oscillator 13 a outputs the signal at the frequency of 9 75 ghz local oscillator 13 b includes a dielectric resonator 2 l b an oscillation device 22 b and a microstrip line 23 b local oscillator 13 b outputs the signal at the frequency of 10 6 ghz a proximal end of conductive.