Microwave Journal

Advances in High-Performance Ceramic Antennas for Small-Form-Factor, Multi-Technology Devices

March 25, 2009

Ethertronics’ Isolated Magnetic Dipole™ (IMD) antenna technology addresses these situations by enabling higher isolation and frequency selectivity while maintaining good efficiency even as the antenna’s size is reduced in order to meet form factor requirements. This paper describes the use of IMD technology for dual-band, dual-feed antennas created from a block of ceramic material.

This surface mountable antenna features a unique dual-feed design, allowing for easier integration. Ethertronics’ IMD antennas also provide reliable, consistent performance because they’re more immune to their surroundings – a major asset in the tight spaces of today’s mobile devices! This operational stability addresses one key drawback of current ceramic antennas: their susceptibility to significantly altered performance when other components are placed in close proximity.

The root cause stems from some antennas’ reliance on the board’s ground plane to excite the radiation mode. This issue creates challenges when developing an RF front end because specification sheets may not include key implementation details, triggering an iterative design cycle to try to improve results.

This paper also proposes new approaches for evaluating ceramic antennas for small-form-factor applications such as cell phones. These are necessary because implementations quickly depart from bare-board measurements, thus rendering product datasheets meaningless in terms of accurately predicting realworld performance.

By offering a simple and fair test method for evaluating ceramic antennas – particularly in terms of their true volume requirements – Ethertronics aims to position ceramic antennas as a viable option for accommodating industry trends toward slim, multi-technology consumer electronics devices.