Passive Balun

Abstract

The invention discloses a passive balance and non-balance converter which is located between a junction circuit and a receiver. The junction circuit decomposes a radio-frequency signal received by an antenna into one sub signal or multiple sub signals. The passive balance and non-balance converter comprises one independent unit structure or multiple independent unit structures, and the number of the unit structures is the same as the number of the sub signals output by the junction circuit. Each unit structure can realize switching from one single-terminal signal to a pair of differential sub signals. The passive balance and non-balance converter has the advantages of being wide in working band, good in linearity and little in insertion loss. Meanwhile, due to the fact that the passive balance and non-balance converter is manufactured on a package substrate, the area of an integrated circuit is reduced, and cost is relatively low.

Description

Technical field [0001] This application relates to a balanced-to-unbalanced converter (balanced-to-unbalanced, abbreviated as balun, also called a balun) applied in the radio frequency field. Background technique [0002] The radio frequency receiver is used to amplify and frequency transform the radio frequency signal received by the antenna to obtain useful signals for subsequent processing. The antenna is generally an unbalanced single-ended form. In order to suppress various noises, the circuit inside the receiver often uses a balanced differential circuit. This requires a balanced-unbalanced converter. After the single-ended signal output by the antenna is converted into a differential signal, the subsequent processing is performed by the balanced differential circuit inside the receiver. The so-called differential signal refers to a pair of signals with the same amplitude and opposite phase. [0003] At present, the common balanced-unbalanced converters are all manufacture...

AI Technical Summary

Problems solved by technology

When passive baluns deal with lower frequency radio frequency signals (such as below 100MHz), or radio frequency signals with a larger bandwidth range (such as 40MHz to 1GHz broadband signals), they need inductors with very large inductance values. To consume a large area of ​​silicon chips to manufacture this inductor, the cost is very high, which is not conducive to fully integrated design

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