Optimization Design Of Limiter Based On PIN Diode

The low noise amplifier is a key device for determining the sensitivity of the RF receiver,which amplifies the small signal received on the RF receiver antenna while reducing noise interference.The more complex the electromagnetic environment in which the low noise amplifier is operating,the greater the likelihood of electromagnetic interference in semiconductor devices in low noise amplifiers.High-power electromagnetic pulses can be easily coupled through the antenna into the front of the RF receiver,and lead to low noise amplifier functional disorder or failure,even permanent physical damage,so the electromagnetic reinforcement of low noise amplifier design attracts more attention.The device of microwave limiter is usually used to protect the low-noise amplifier from the front of the RF receiver from high-power signal damage.In this thesis,the PIN diode passive limiter is chosen as the research object,and the performance of limiter is optimized by transforming the structure of limiting circuit and using different types of limiting diodes.The main research work and conclusions are as follows:(1).The limiting circuits are established by using ADS software,and the performances of the limiting circuits under small signal injection,continuous wave injection and pulse injection are studied by S-parameter simulation,harmonic balance simulation and transient simulation,respectively.In the process of limiting circuit optimization,using PIN dual-diode instead of inductor provides a DC loop and increases the power capacity of the limiter circuit,and replacing PIN diodes with Schottky diodes reduces spike leakage energy and response time for limiter circuits.Meanwhile,the method of cascade limiting structure is used to further improve the power capacity and isolation of the limiter circuit.Finally,a three-stage hybrid dual-diode limiter circuit with optimal performance is designed,and by adjusting the microstrip line geometry size to further optimize the limiting circuit of the limiting performance.The performance of the three-stage hybrid dual-diode limiter circuit is compared with that of several commercial microwave limiters,and the comparison result shows that the performance of the designed limiting circuit is excellent.(2).The Kink Effect which appears in the output power curve of the PIN limiter is studied.In this thesis,the causes of this effect are briefly analyzed,and the factors influencing Kink Effect are studied.The research conclusions show that the input power value corresponding to the Kink Effect is different because of different types of the diodes in the limiting circuit,and the number of Kink Effect occurrence varies with differences of limiting circuit cascade stages.If the circuit structure is different,the input power is different when Kink Effect appears.(3).The influence of the factors such as the intrinsic layer thickness of PIN diode,temperature and HPM signal power,frequency,pulse width and rising edge time on the limiting performance of the single-stage PIN dual-diode limit circuit are studied by using the control variable method.The researches show that the limiting circuit used PIN diode with large thickness of intrinsic layer has a good power capacity but its spike leakage energy is large.The performance of limiting circuit enhances as the PIN diode junction temperature increases.The spike leakage performance is less affected by temperature.The greater power of the injected signal,the greater the peak power and energy of the circuit spike leakage.Considering the influence of signal frequency on the clipping performance in the operating frequency band should be combined with the power of the injected signal.The pulse width and rising edge delay of HPM signal have little effect on the spike leakage performance of the circuit.The results of this thesis have certain guiding significance for designing limiter and improving the performance of limiter in practice.