Investigation of Miniaturized Differential Transformer Coupled Configuration Circuit Using IPD Technology in Advanced Package Integration

System-in-package (SiP) is an advanced packaging technology that integrates multiple chips and components into a single package, creating a highly integrated system. Integrated Passive Devices (IPD) technology is commonly used to design resistors, inductors, capacitors, and other passive circuits, enabling the development of new products and solutions that was not possible with traditional board solutions. In recent years, IPD technology has become an important way to achieve SiP. This paper presents a practical implementation of the Differential Transformer Coupled Configuration Circuit using IPD techniques in a RF signal processing SiP, which minimizes the system board area and improves system performance. The paper demonstrates a typical ADC differential input and DAC differential output differential transformer coupled circuit IPD design. The Balun chip and related discrete RLC components are designed as one IPD chip, which can be integrated with the ADC and DAC through a silicon interposer or plastic substrate using Flip chip mode or wire bond in Advanced Package. The dual-channel ADC signal input coupled circuit IPD design meets the application requirements of bandwidth ranging from 1.8 GHz to 5 GHz and return loss and amplitude balance less than 2.5 dB and 3 dB, respectively. The double-input channel coupled circuit chip using fanout integration process can be implemented using RDLs in Advanced Packaging. The results offer a new way for coupled circuit design that significantly reduces the design complexity and area of the system PCB board.