This document describes an antenna design that can be used with all transceivers, transmitters, and SoC from Texas Instruments which are capable of

operating in the 868 and 915 MHz band. The antenna has been implemented on a USB dongle with CC1111 [1], which is a sub 1 GHz SoC with USB controller. All measurement results presented in this document are based on measurements performed on the CC1111 USB dongle.

Maximum gain is measured to be 0.7 dB and the overall size requirement for this antenna is 8.5 mm x 7.8 mm. The antenna solution consists of a chip antenna from Johanson Technology in conjunction with a special PCB trace.

The original design is optimized for operation in the 868 MHz band, but it is easy to tune the antenna for operation in the 915 MHz band by reducing the length of the PCB trace. Thus, this is a flexible, compact, medium cost, and high performance antenna solution.

http://www.ti.com/lit/swra160