An Integrated Directional Coupler Based on Standard CMOS Technology

Abstract

The present invention provides a full-on-wafer integrated directional coupler technology for a standard CMOS process and an integrated circuit, belonging to the field of radio frequency communication technologies. The core of the present invention is: a standard CMOS process technology is used, and a CMOS integrated directional coupler is formed of a coil 1 formed by winding a metal wire of an upper layer, a coil 2 formed by winding a metal wire of a lower layer, two tuning capacitor arrays and a matching resistor; two ports of the coil 1 are a direct end and an input end, and two ports of the coil 2 are a coupled end and an isolated end; an angle of 90° exists between the ports of the coil 1 and the ports of the coil 2; the coil 1 is formed by winding metal of a high layer, the coil 2 is formed by winding metal of a bottom layer, the insertion loss is small, and the isolation is large; a capacitor between the direct end and the input end is used for frequency tuning; a capacitor between the coupled end and the isolated end is used for isolation tuning; the coil 1 and the coil 2 adopt a three-dimensional structure, the metal wire of the upper layer and the metal wire of the lower layer partially overlap, and the change of the coil shape, the number of turns, and the line width, the use of different metal layers and the extent of the overlapping between metal wires of different layers may flexibly change performance parameters such as insertion loss, isolation, and coupling. The standard CMOS process integrated directional coupler implemented by the present invention is characterized in that single chip integration on the silicon-based CMOS / BiCMOS process is enabled, the insertion loss is small, the isolation is large, the directivity is good, the tuning performance is strong, the applicability is strong, and the cost is low.

Description

Technical field [0001] The invention belongs to the technical field of radio frequency integrated circuits, and relates to a directional coupler, in particular to an all-on-chip integrated directional coupler based on a standard CMOS process. Background technique [0002] Directional Coupler (Directional Coupler) is a widely used radio frequency device, which can be used for signal isolation, signal separation, etc., so that the radio frequency receiver and transmitter can work in the same frequency band at the same time. The principle of directional coupler applied to transceiver system is as follows: figure 1 As shown, "Input" (Input) is connected to the transmitter output (TX), "Direct" (Direct) is connected to the antenna (Antenna), "Coupled" (Coupled) is connected to the receiver input (RX), "Isolation Terminal" (Isolated) is connected to the matching resistor (Res). Among them, the loss between the input end and the through end is "Insertion Loss", the loss between t...

AI Technical Summary

Problems solved by technology

In order to be able to integrate directional couplers on-chip, some people have used some special processing techniques before, such as Shim, S., etc. (Shim, S., Hong, S., "A CMOS Power Amplifier With Integrated-Passive-Device Spiral-Shaped Directional Coupler for Mobile UHF RFID Reader, "Microwave Theory and Techniques, IEEE Transactions on, vol.PP, no.99, pp.1, 0) sets forth a kind of directional coupler utilizing IPD (integrated passive device) technology to make, Although the volume is small, the special process technology used is not compatible with the standard CMOS process, the cost is high, the processing process is complicated, and the on-chip integrated directional coupler cannot be realized, and the practicability is poor

[0004] At present, the existing technology has not well solved the problem of preparing directional couplers under the standard CMOS process, which greatly limits the application of these technologies, such as the inability to meet the requirements of miniaturization and portability in the field of mobile communication systems etc.; while some achieve the goal of miniaturization, they are manufactured using special processes, which are costly and cannot meet the requirements of system integration

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