Broadband active matching method and matching circuit for electronically small receiving antenna based on negative impedance conversion

Abstract

The invention provides broadband active matching method and matching circuit for an electronically small receiving antenna based on negative impedance conversion. An amplifier which is directly connected with a capacitive electronically small antennae is introduced into a negative impedance conversion so as to enable the amplifier to become a negative impedance conversion amplifier, and the negative impedance conversion obtains a negative capacitance on the input end of the amplifier; when an absolute value of the negative capacitance is greater than the input capacitance of the amplifier, the input end of the amplifier obtains equivalent negative capacitance, the equivalent positive capacitance (input by the electronically small antenna) of an electric reactor is counteracted by the negative electricity capacitance, and the input end of an active electric network is provided with an equivalent negative capacitor According to the method and the circuit, the active receiving antenna has a broadband character and has similar gain and similar signal-to-noise performance with an enhancement mode Non-Foster (negative impedance) matching method, but a circuit is relatively simple; and the combination property is good, the amplification and the negative impedance conversion can be realized in the same circuit, and only a positive feedback capacitor is added compared with the classical active receiving antenna.

Description

technical field [0001] The invention relates to a broadband matching method for an electrically small antenna, and also relates to a broadband matching circuit for an electrically small antenna. Background technique [0002] With the miniaturization of radio technology equipment, the requirements for antenna size in small spaces, and the wide frequency band of communication equipment, there is an increasing demand for broadband miniaturized antennas, which makes broadband and miniaturized antennas become a research hotspot at home and abroad. one of the subjects. In order to realize the miniaturization of the antenna, the electrically small antenna is widely used, but the electrically small antenna has the disadvantages of large input reactance and small radiation resistance, so that the passively matched electrically small antenna is limited by the gain bandwidth theory, and cannot achieve broadband and high efficiency. The classic active receiving antenna uses a high inp...

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Problems solved by technology

The document "Sussman-Fort, S.E. "Non-Foster vs. active matching of an electrically-small receive antenna" Antennas and Propagation Society International Symposium (APSURSI), pp1–4, 2010", proposed an enhanced Non-Foster ( Negative impedance) matching method can improve the gain and signal-to-noise ratio very well. Compared with the classic active receiving antenna, the output signal-to-noise ratio has about 5dB improvement. It is realized by inserting a floating negative impedance converter between the antenna and the amplifier circuit, and the inserted floating negative impedance converter makes the circuit structure complex and the nonlinear performance deteriorates

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