Multi-Tech Systems MTCBA-G-EN-FX manual Appendix B Wireless Antenna, GSM, EDGE, and Cdma Antenna

Appendix B – Wireless Antenna

Appendix B – Wireless Antenna

The Antenna

The antenna sub-system and integration in the application is a major issue: Choice of antenna (type, length, performances, thermal resistance, etc.) These elements could affect GSM performances such as sensitivity and emitted power.

PTCRB Requirements Note:

There cannot be any alteration to the authorized antenna system. The antenna system must be the same type with similar in-band and out-of-band radiation patterns and maintain the same specifications.

FCC Requirements Note:

The antenna gain, including cable loss, must not exceed 3.0 dBi at 1900 MHz / 1.6 dBi at 850 MHz for mobile operating configurations and 7.0 dBi at 1900 MHz / 2.3 dBi at 850 MHz for fixed mounted operations, as defined in 2.1091 and 1.1307 of the rules for satisfying RF exposure compliance.

GSM, EDGE, and CDMA Antenna

The integrated modem antenna connector is a SMA connector. The SMA connector incorporates a 'Screw-on' action in order to make the connection easier while providing an excellent RF performance. An additional advantage is its small physical size, which is 50% of the standard MCX connector.

This type of connector is suitable for the standard ranges of flexible and semi-rigid cables. The characteristic impedance of the MMCX coaxial connector is 50 ohm. The antenna manufacturer must guarantee that the antenna will be working according to the radio characteristics presented in the table below.

GSM and E-GSM Radio Characteristics

	GSM 850	E-GSM 900	GSM 1800	GSM 1900
Frequency RX	869 to 894 MHz	925 to 960 MHz	1805 to 1880 MHz	1930 to 1990 MHz
Frequency TX	824 to 849 MHz	880 to 915 MHz	1710 to 1785 MHz	1850 to 1910 MHz
RF Power Stand	2W at 12.5% duty cycle	2W at 12.5% duty cycle	1W at 12.5% duty cycle	1W at 12.5% duty cycle
Impedance		50 ohms
VSWR		<2
Typical Radiated Gain		0 dBi on azimuth plane

CDMA Radio Characteristics

	CDMA 800		CDMA 1900
Frequency RX	869 to 894 MHz		1930 to 1990 MHz
Frequency TX	824 to 849 MHz		1850 to 1910 MHz
Impedance		50	ohms
VSWR		<2
Typical Radiated Gain	0 dBi in at least one direction

Multi-Tech Systems, Inc. MultiModem Wireless Modem with Ethernet Interface (S000375F) 53