A Nonstandard Phase-Difference Ring Coupler for Unequal Power Division

ABSTRACT

A planar ring coupler with nonstandard phase difference and an unequal power division ratio is proposed in this article. The circuit topology of this coupler is similar to the traditional coupler, which consists of four arms in microstrip implementation. The design parameters of this coupler can be determined easily by closed-form equations. Based on standard microstrip technology, the interrelated constraint between phase difference and realizable power division ratio has been investigated. The fractional bandwidth analysis in terms of phase difference and power division is provided. Two prototypes with this proposed structure, operating at 1 GHz, have been designed, simulated, and implemented using microstrip lines. The measurement shows good agreement with the numerical results, which demonstrates the validity of this design.

KEYWORDS:

• Arbitrary power division
• compact structure
• nonstandard phase difference
• ring coupler

Additional information

Funding

This work was supported in part by the program for Changjiang scholars and innovative research team in university (IRT1212) and the project of construction of innovative teams and teacher career development for universities and colleges under Beijing Municipality (IDHT20130518).