Electrically tunable filter

Abstract

The invention provides an electrically tunable filter, relating to the technical field of electrocommunication, aiming at solving the technical problems of narrow tunable bandwidth, the frequency being less than 1G, bad reliability, big insertion loss, limited signal receiving range and the like existing in the prior electrically tunable filter products. N series inductances are connected in series between the radio frequency input end and the radio frequency output end in the invention; N-1 parallel inductances and N-1 three-terminal circuits are connected in parallel between N series inductances; one end of each parallel inductance is connected between the above two adjacent series inductances and the other end thereof is connected to the ground; one of the three-terminal circuits is a variable capacitance diode, the input end thereof is connected between the input ends of the above adjacent parallel inductances and the input ends of the parallel inductances, and the output end thereof is connected with the other circuit of capacitance of the three-terminal circuit and then is connected to the ground; and the input end of the filter inductance is connected between the output endof the variable capacitance diode and the input end of the capacitance, and the output end thereof is connected with a voltage control end. The invention is applicable to the fields of microwave communication, ultra wideband receivers, electronic devices and the like.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to an electric tuning filter used in microwave communication, ultra-wideband receiver, electronic equipment and the like. Background technique [0002] The electric tuning filter is a key component in the communication system. Since the center frequency of the electric tuning filter is adjustable, the signal of the specified frequency can pass through the device, and the energy other than the specified frequency signal is reflected, thus realizing the function of countless frequency selection. . The current ESC filters on the market mainly have the following problems: [0003] 1. Narrow adjustable bandwidth; [0004] 2. The frequency is less than 1G; [0005] 3. Poor reliability; [0006] 4. The insertion loss is large, the signal receiving range is limited, and the noise figure of the receiver is large. Contents of the invention [0007] The present invention aims to s...

AI Technical Summary

Problems solved by technology

[0007] The present invention aims to solve technical problems such as narrow adjustable bandwidth, frequency less than 1G, poor reliability, large insertion loss, limited signal receiving range, and large receiver noise coefficient existing in existing electronically adjustable filter products, so as to provide a plug-in Electric adjustable filter with small loss, small size, wide adjustable frequency range, good reliability, small insertion loss, large signal receiving range, reduced receiver noise figure, and wide frequency range

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