RCQ1A Microwave Leakage Energy Tester

Overview

RCQ1AFor broadband microwave leakage tester (microwave leakage tester), broadband microwave leakage tester（Microwave leakage tester）It is used to measure frequency from915MHz～12.4GHzMicrowave leakage power density of continuous wave（10μW/cm²～100mW/cm²），RCQ1AFor broadband microwave leakage tester (microwave leakage tester)Can be used by microwave radiation protection research institutions, microwave application departments in national defense, industry, and medical fields, as well as relevant factories, universities, and research institutes to measure the leakage power density of microwave equipment,RCQ1AFor broadband microwave leakage tester (microwave leakage tester)Portable, easy to use, with eight sections1.5VPowered by dry batteries, it can also be used220V_～AC power supply.

twoTechnical Parameter

1Technical indicators

RCQ1AFor broadband microwave leakage tester (microwave leakage tester)It consists of an indicator and a microwave probe.

（1）The indicator consists of a field-effect transistor and a transistor directly coupled amplifier.

（2）The microwave probe consists of two pairs of orthogonal dipole antennas and bismuth antimony thermocouples sprayed on the thin film dielectric body, as well as a protective cover, a handle, and a plug.

2Measurement frequency range:915MHz～12.4GHz.

3Measuring power density range:10μW/cm²～100mW/cm²±2.5dB.

4Indicators are divided into100μW/cm²、500μW/cm²、1mW/cm²Full three levels.

5Microwave probe, the instrument is equipped with three microwave probes with different sensitivities to expand the range. The range of each probe is as follows:

×1microwave probe10μW/cm²～1mW/cm²

×10microwave probe100μW/cm²～10mW/cm²

×100microwave probe1mW/cm²～100mW/cm²

One zero power density simulator with instrument adjustment capacity, one microwave calibration table, and one voltage regulator.

6、RCQ1AFor broadband microwave leakage tester (microwave leakage tester)Can work continuously in the following environments8Hour.

（1）Environmental temperature:-10^OC～+40^OC

（2）Relative temperature: ≤80％（+40^OC）

（3）Atmospheric pressure:750±30mmHg

7、RCQ1AFor broadband microwave leakage tester (microwave leakage tester)The power supply is12VThe working current is10mALeft and right, using eight sections1.5VPowered by dry batteries or voltage regulators, the power consumption of the instrument is approximately12VAThis instrument does not come with a dry battery when it leaves the factory.

8The external dimensions of the instrument:160×120×232（mm）.

9The weight of the instrument is approximately three microwave probes connected to the indicator4kg,Connect storage boxes approximately6kg.

Three working principles

To measure microwave leakage power density accurately without interfering with or damaging the measured field, a short antenna is usually used as the receiving unit. The receiving unit of the microwave probe of this instrument consists of two pairs of orthogonal dipole antennas and bismuth antimony thermocouple elements sprayed on a thin film dielectric substrate to form a dipole antenna. Receiving microwave energy and dissipating it in bismuth antimony elements, the bismuth antimony elements perform thermocouple electrical conversion to generate thermoelectric electromotive force (weak DC potential). The weak DC signal output by the bismuth antimony thermocouple is then input to a high-sensitivity DC chopper amplifier for power density direct reading indication.

1Microwave probe section

The microwave probe is composed of two films sprayed into a certain pattern on top of each other (see figure)1）When the microwave probe is not placed in the microwave leakage radiation field, the bismuth antimony thermocouple element has no temperature difference and therefore no potential output. When the microwave probe is placed in the microwave leakage radiation field and the small dipole antenna receives microwave power, the bismuth antimony thermocouple element generates a temperature difference (Peltier effect) between the hot and cold nodes, resulting in a temperature difference electromotive force (Seebeck effect). Since two pairs of bismuth antimony thermocouple elements are connected in series, their total electromotive force is equal to the sum of each pair of electromotive forces,Lassemble=L₁+L₂The tangential component of the electric field strength on the dipole antenna connected to each pair of thermocouples and the DC output of each thermocouple（L₁+L₂）The square is proportional, and the synthesized output is used as powerPDirected out (see figure)2Schematic diagram of orthogonal antenna principle.

P=K（|L₁|²+|L₂|²）=K[|E|²（sin²θ+cos²θ）]=K|E|²

As can be seen from the above equation, when the electric field strength loss of the measured field is within the plane composed of two pairs of dipole antennas, as long as the symmetry of the two pairs of bismuth antimony thermocouple elements is relatively consistent, their power density indication is basically not affected by polarization (i.e. no directionality). However, due to manufacturing difficulties, the two pairs of bismuth antimony thermocouples cannot achieve considerable symmetry and consistency, so this microwave probe still has a certain degree of directionality.

2Indicator section

The indicator is a DC chopper amplifier using a junction field-effect transistor DC chopper amplifier circuit, as shown in the block diagram3The input signal is connected to a modulator, which modulates the DC signal into an AC signal. The modulator is coupled to an AC amplifier through a capacitor for amplification. The amplifier uses a direct coupled multi-stage amplifier, and the amplified signal is coupled to a dielectric through a capacitor. The function of the dielectric is to convert the AC signal into a DC signal to drive the meter head.

The circuit adopts local feedback and full feedback circuits to control the gain of the amplifier, suppressing the noise and external interference of the transistor itself. The gain stabilization zeroing circuit adopts AC zeroing method, and the amplifier gain is about40dBLeft and right, the power supply for the indicator uses eight sections1.5VDry batteries are connected in series or powered by a voltage regulator.

Four structural features

This microwave leakage energy tester is portable and consists of a microwave probe and an indicator. The indicator and the microwave probe are separate pieces that can be used together to measure the leakage field.

The indicator panel is equipped with a header and an input socket. The work selection switch box zero potentiometer, all other components are installed on the bottom plate inside the instrument, including a dry battery box, a voltage regulator socket, a potentiometer for adjusting the sensitivity of the gear, and an amplifier circuit board. The amplifier circuit board is shielded with a copper box to effectively prevent interference from external electromagnetic fields.

The microwave probe consists of two pairs of orthogonal dipole antennas and bismuth antimony thermocouples vacuum deposited on a thin film dielectric substrate. Its structure includes a dielectric head, a membrane fixing seat, a cap, a protective tube, and a handle. The protective tube contains a low-pass filter and a plug, which includes a microwave efficiency calibration potentiometer and a dial.