Siemens HC15 Spécifications télécharger pdf (Page 32)

HC15 Hardware Interface Description

4 Antenna Interface

HC15_HD_v01.000 Page 32 of 67 2007-1-19

Confidential / Released

4 Antenna Interface

The RF interface has an impedance of 50Ω. HC15 is capable of sustaining a total mismatch at the antenna con-

nector or pad without any damage, even when transmitting at maximum RF power.

The external antenna must be matched properly to achieve best performance regarding radiated power, DC-

power consumption, modulation accuracy and harmonic suppression. Antenna matching networks are not

included on the HC15 PCB and should be placed in the host application.

Regarding the return loss HC15 provides the following values in the active band:

The connection of the antenna or other equipment must be decoupled from DC voltage. This is necessary

because the antenna connector is DC coupled to ground via an inductor for ESD protection.

Note: The antenna must be isolated for ESD protection (to withstand a voltage resistance up to 8kV air dis-

charge).

4.1 Antenna Installation

To suit the physical design of individual applications HC15 offers two alternative approaches to connecting the

antenna:

• Recommended approach: U.FL-R-SMT antenna connector from Hirose assembled on the top side of the

PCB. See Section 4.3 for connector details.

• Antenna pad and grounding plane placed on the bottom side. See Section 4.2.

The U.FL-R-SMT connector has been chosen as antenna reference point (ARP) for the Siemens reference

equipment submitted to type approve HC15. All RF data specified throughout this manual are related to the ARP.

IMPORTANT: Both solutions can only be applied alternatively. This means, whenever an antenna is plugged to

the Hirose connector, the pad must not be used. Vice versa, if the antenna is connected to the pad, then the

Hirose connector must be left empty.

No matter which option you choose, ensure that the antenna pad does not come into contact with the holding

device or any other components of the host application. It needs to be surrounded by a restricted area filled with

air, which must also be reserved 1.4mm in height.

Figure 14: Restricted area around antenna pad (side and bottom view)

Table 6: Return loss in the active band

State of module Return loss of module Recommended return loss of application

Receive >

8dB > 12dB

Transmit not applicable >

12dB

Idle <

5dB not applicable

1 2 ... 27 28 29 30 31 32 33 34 35 36 37 ... 66 67

Pas de commentaire

Siemens HC15 Spécifications Page 32