Broadband high-balance on-chip transformer Balun

Abstract

The invention relates to a broadband high-balance on-chip transformer Balun, and belongs to the field of radio frequency devices. The broadband high-balance on-chip transformer Balun comprises two primary coils and a secondary coil. The two primary coils are formed in the manner that inductors with center taps are broken near the center taps, and the secondary coil is a plane spiral inductor with a center tap. The primary coils and the secondary coil are embedded to improve the coupling coefficient. The center taps of the primary coils and the center tap of the secondary coil are connected together and finally connected to the ground plane. According to the scheme design, the transformer Balun can solve the problems that when an existing transformer Balun works at the low frequency, the working band is narrow, the phase balance degree is poor, and insertion losses and return losses are large. The broadband high-balance on-chip transformer Balun can be used on an occasion where single end-difference conversion needs to be finished in the design of an on-chip integrated circuit.

Description

technical field [0001] The invention belongs to the field of radio frequency devices, and relates to an on-chip passive balun (Balance-to-Unbalance, hereinafter referred to as Balun), in particular to an on-chip transformer balun with broadband, low loss, and high balance performance. Background technique [0002] The balun is often used in the occasion where the front end of the RF transceiver needs to perform single-ended and differential signal conversion. There are mainly two types of baluns with existing structures, namely: Marchand balun and transformer balun. The advantage of Marchand Balun is that it has a wide operating bandwidth and low reflection. As reported in the article "Balance-Compensated Asymmetric Marchand Baluns on Silicon for MMICs", at present, on-chip Baluns have been widely used in millimeter-wave circuits, thanks to the inverse proportional relationship between the size of passive devices and the operating frequency. However, as described in the ar...

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Problems solved by technology

[0010] The purpose of the present invention is to propose an on-chip transformer balun with broadband and high balance, so as to solve the problem that the existing transformer balun cannot achieve low loss, low reflection and high balance at the same time in low-frequency applications such as S-band.

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