User's Manual

USER MANUAL 1.34

STM 300 / STM 300C / STM 300U

4.5.4 Chip antenna (supplier: Mitsubishi Material, Type AM11DG-ST01)

315 MHz

Modular approval not available. Range and gain significantly reduced because of antenna

size vs. the wavelength. Small chip antennas at this frequency may be suited for space-

constrained applications. Check with supplier for matching circuit and board design

guidelines. Supplier can make recommendations or do testing to optimize individual PCB

design.

868.3 MHz

Additional matching circuit and proper board design is required.

Check with supplier for matching circuit and board design guidelines.

Connect matching circuit to RF_50 using 50 Ohm strip lines. Please follow 902 MHz

board design recommendations and dimensions. Be aware that matching values differ!

902.875 MHz

Limited modular approval is available. Please contact EnOcean to sign the mandatory

limited modular approval user agreement. Dimensions may not be shortened. Matching

circuit is part of the limited modular approval and may not be changed. Minimum top

and bottom side ground plane required as shown below. Connect ground planes using

multiple via as shown. Connect matching circuit to RF_50. Use High Q wire wound in-

ductors, e.g. 0603 Murata LQW18A series. Matching circuits values: L1 = 3.9nH; L2 =

33nH, L3 = 12nH. This antenna evaluation board is available upon request for use with

EnOcean EDK 350 developer kit.

For any further questions or chip antenna quotes, please refer to Mitsubishi Materials

website at