Harmonic inhibition power amplifier

Abstract

The invention discloses a harmonic inhibition power amplifier and belongs to the field of wireless emission. Input signals in the harmonic inhibition power amplifier, after passing through a first microstrip low-pass filter, enter a first-grade power amplifier, then, after passing a second microstrip low-pass filter, enter a second-grade power amplifier, and after being subjected to cluster filtering through a third microstrip low-pass filter, are output. Filter casuists and capacitors are added to a drain electrode feed end of the first-grade power amplifier, a control electrode feed end of the first-grade power amplifier, a drain electrode feed end of the second-grade power amplifier and a grid electrode feed end of the second-grade power amplifier. According to the invention, through microstrip low-pass filters connected in series between the power amplifiers of corresponding grades of the power amplifier provided by the invention, the share of harmonic components transmitted to a circuit of a next grade is reduced, and at the same time, the feed ends of two-stage power amplifiers, besides employing routine filter capacitor combinations, are also additionally provided with sector microstrip filtering branches of fundamental frequency, secondary harmonics and triple harmonics of dot frequency signals so as to reduce power of leakage of the fundamental frequency and the harmonics to a receiver end from a feed circuit.

Description

technical field [0001] The invention belongs to the field of wireless transmission, and in particular relates to a harmonic suppression power amplifier applied to harmonic radar. Background technique [0002] Harmonic radar is a radar system that transmits fundamental wave signals, receives 2nd, 3rd or even higher harmonic / combination wave signals re-radiated from targets, and judges, identifies and detects targets. The upgraded product of the linear node detector has the advantages of higher sensitivity and lower false alarm rate. [0003] Due to the close distance between the transmitting antenna and the receiving antenna of the harmonic radar, as well as the sensitivity requirements of the detection equipment, higher requirements are put forward for the harmonic suppression of the transmitting module. The power amplifier is an important part of its transmitting module. Because of its nonlinear characteristics, it will generate second harmonics and third harmonics, and th...

AI Technical Summary

Problems solved by technology

The power amplifier is an important part of its transmitting module. Because of its nonlinear characteristics, it will generate second harmonics and third harmonics, and the harmonic radar receiver judges objects by receiving the second harmonics or third harmonics emitted by objects. Whether it exists or not, if the harmonics generated by the power amplifier are not filtered well at the feed end of the power amplifier, such as figure 1 As shown in the power amplifier, these harmonics will enter the receiver through the feed terminal, thereby reducing the sensitivity of the receiver, and even causing false measurements

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