BALANCED MIXER

Abstract

An experimental study of a balanced mixer based on 2A116A-1 diodes was carried out.
Conversion losses were measured in the input frequency range of 2450 ± 45 MHz during down
conversion to an intermediate frequency of 2125 MHz. Conversion loss does not exceed 20 dB in a
narrow band of 2440±10 MHz. The amplitude characteristic of the mixer was taken, from which it
can be seen that it is linear for input signals up to 0 dBm (1 mW). The dependence of conversion
losses on the local oscillator power is studied. It is shown that the minimum losses are observed at
a local oscillator power of 13 dBm (20 mW). The combination frequency spectrum at the mixer
output does not contain parasitic conversion products above minus 50 dB with respect to the useful
signal in the 100 MHz bandwidth. The mixer is recommended for use in receiving and transmitting
equipment and measuring equipment. Comparison with other mixers shows a noticeable advantage
- high selectivity in relation to out-of-band signals. This is achieved by applying two band
pass filters and a low pass filter. Three filters were simulated in the Microwave Office software
package. Models and amplitude-frequency characteristics of three filters from Microwave Office
are given. The mixer is made in a frame-type case made of aluminum. It has two ceramic boards
sized 24x30 mm (material 22xc). The method of manufacturing a printed circuit board pattern is
thin-film technology. The case is closed by two tight covers. All three connectors are type
IX GOST13317, socket.