A three-port power divider consisting of a directional coupler, a Wilkinson power divider, and two transmission lines connected to them is proposed. Theoretical analysis reveals that highly unequal power division can be achieved by a feedback mechanism of two transmission lines along with the coupling coefficient of the directional coupler and the power division ratio of the Wilkinson power divider. The three-port power divider inherits the performance characteristics of high isolation, low reflection coefficients at all ports, and the minimum number of components. The proposed power divider is designed at 5.8 GHz and fabricated and evaluated through measurements. It demonstrates that electromagnetic simulation results are in good agreement with theoretical prediction and measurement results. The three-port power divider is compact in the planar form, so it can be easily integrated into radio frequency front ends.

This paper presents a board-to-board interconnect technique utilizing elastomeric connectors and parallel microstrip lines on a flexible foil cable with low dielectric loss (tanδ = 0.002). It is shown that a pad structure combined with an elastomeric connector can be codesigned such that a good signal integrity and thus a high data transmission rate is achieved. It is also shown that 2 Gbps data transmission rate can be achieved with a 490mm-long microstrip on the flexible cable, where crosstalk is taken into accont. Utilizing the elastomeric connector together with the flat and flexible cable, dense parallel microstrips can easily be designed and processed since standard printed circuit board processing techniques can be utilized.