User's Manual
15.0 RF Frequency Detail
The following table shows the RF channels as defined by the IEEE 802.15.4 standard.
RF channel Frequency
11 2405MHz
12 2410MHz
13 2415MHz
14 2420MHz
15 2425MHz
16 2430MHz
17 2435MHz
18 2440MHz
19 2445MHz
20 2450MHz
21 2455MHz
22 2460MHz
23 2465MHz
24 2470MHz
25 2475MHz
26 2480MHz
The output power level can be configured in the range -32 to 5 dBm. The RF transceiver
uses direct sequence spread spectrum (DSSS) with 2 Mchip/s chip rate, giving a raw data
rate of 250 kbit/s. The modulation format is Offset – Quadrature Phase Shift Keying
(O-QPSK). It is robust even under noisy environments when sharing the same frequency
band with other applications.
The use of RF frequencies and maximum allowed RF power should according to different
national regulations. The CT-260 is complying with the applicable regulations for the world
wide 2.4GHz ISM band.
[Subject to final approval: Specifically it complies with the European Union R&TTE directive
meeting EN 300 328 and EN300 440 class 2. It also meets the FCC CFR47 Part15
regulations for use in the US and the ARIB T-66 for use in Japan.]
16.0 Antenna Design Considerations
CT-EM260 provides an integrated antenna. The design should be effective for many
applications requiring a compact solution containing all the critical RF parts within the
module. Applications requiring better range may consider an external antenna or possibly
even an external booster circuit (power amplifier).
The range testing using the integrated antenna shows a typical distance of 100 m outdoor
line-of-sight (LOS). If the application is used indoor, the range will be around 10 to 30 m,
depending on structure and building materials.
The module with antenna is matched for use in the 2.4 GHz band. Due to the dielectric
ceramic material the antenna is shorter than a normal quarter wave antenna. However, it