An improved printed balun for a dual device load board

This paper describes the design of an improved planar Marchand balun for use in an efficient, lowcost, high-volume Automated Test Equipment (ATE) solution. Two different devices, sharing the same footprint, designed for broadband wireless access using the IEEE 802.16 d/e protocols at different frequency bands are production tested using the same load board. Two narrowband hybrid ring rat race baluns are switched using RF relays depending on the device being tested. A new test solution using an improved planar Marchand balun that delivers improved performance without the need for switching baluns is proposed here.