A Symmetrical Integrated Laminated Transformer

Abstract

The invention discloses a symmetrical integrated laminated transformer, which consists of a substrate, first to third layers of dielectrics sequentially arranged on the substrate from bottom to top, and grid-shaped shielding grids respectively placed in the first layer of dielectrics, The primary coil in the second layer of medium and the secondary coil in the third layer of medium are composed; wherein, the shielding grid is arranged on the lower plane of the first layer of medium; the primary coils are separated from each other and are symmetrical with 2 turns around the axis and arranged in parallel on the lower plane of the second layer of medium; the secondary coils are separated from each other and symmetrically around the axis for 5 turns and arranged in series on the lower plane of the third layer of medium, and the adjacent coils in groups of two The coil is cross-connected with two connecting wires near the axis, and the remaining coil is directly connected with the connecting wire with the metal layer near the axis, and the center tap of the secondary coil is set at the middle point. The symmetrical integrated laminated transformer of the invention has the characteristics of good symmetry, high turns ratio and high magnetic induction coefficient.

Description

technical field [0001] The invention belongs to the technical field of radio frequency analog integrated circuits. It relates to a transformer, and more particularly relates to a symmetrical integrated laminated transformer. The invention is mainly applied in the broadband low-noise amplifier or mixer at the front end of the radio frequency receiver to convert the current or voltage of the radio frequency signal. Background technique [0002] Integrated transformers in radio frequency and microwave integrated circuits can be implemented in tiled, interleaved, and stacked types, among which the stacked type has the largest magnetic inductance. Such as literature [1] J.R.Long, "Monolithic transformers for silicon RF IC design", IEEE Journal of Solid-State Circuits, 35(9), pp.1368-1382, 2000 and literature [2] J.J.Zhou, "Monolithic transformers and their application in differential CMOS RF low-noise amplifier", IEEE Journal of Solid-State Circuits, 33(12), pp.2020-2027, 1998 ...

AI Technical Summary

Problems solved by technology

[0003] 1) The induction coil is asymmetrical and is not suitable for use in a symmetrical broadband circuit (such as a broadband fully differential amplifier) ​​to suppress common-mode signals;

[0004] 2) The parasitic capacitance of the induction coil relative to the substrate is large, because the size (or area) of the integrated laminated transformer with a high turns ratio is large (its outer diameter is generally greater than 200 μm), so both the parasitic capacitance and the parasitic resistance Larger (the parasitic capacitance of the secondary coil relative to the substrate is generally greater than 0.1pF, and the parasitic resistance of the secondary coil is generally greater than 20Ω), resulting in a lower resonance frequency (generally lower than 4GHz), which limits the integrated stacking to a certain extent Transformer performance and operating frequency range;

[0005] 3) There is no center tap, so there is only one set of outputs, and the application is limited

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