User`s manual

Page 8 of 36 A2541R24x – User’s Manual
Release Date 11/22/13
Figure 2 The functionality of the A2541R24C, using an external antenna
The description of the functional blocks shown in Figure 1 and Figure 2 is given as follows:
 Antenna
o The antenna couples energy between the air and the module. The integral
antenna and the external monopole antenna, both centered at 2441.75 MHz,
provide a near omni-directional antenna pattern with high efficiency such that the
application will work in any direction. Note that the end radiation pattern depends
not only on the antenna, but also the ground plane, enclosure and installation
environment.
 Matching & Filtering
o The matching provides the correct loading of the transmit amplifier to achieve the
highest output power as well as the correct loading for the receive LNA to
achieve the best sensitivity.
o Filtering removes spurious signals to comply with regulatory intentional radiator
requirements, provides reduced susceptibility to power supply and digital noise,
and filters out RF and high frequency noise from the communication data and
control link.
 TX/RX Chain
o TX/RX chain handles transmitting and receiving of the communication data
based on the radio register settings. It involves the coordination of several blocks
including modulator, demodulator, AGC control, frequency synthesizer and frame
control.
 Crystal
o Crystal oscillator provides the necessary clock reference for the whole module
operation. The A2541R24A and A2541R24C modules use two crystals: a 32
MHz crystal and a 32.768 kHz crystal.
 Power Management