User's Manual

Figure 2. MG2455(U11) Block Diagram
2. RF Power AMP(U13)
SKY65348(U13) is a high performance, Transmit/Receive(T/R) Front-End Module (FEM) ideally
suited for use in 2.4 GHz Industrial, Scientific, and Medical (ISM) applications.
A Double-Pole, Double-Throw (DPDT) switch allows antenna diversity and is used to select
between receive and transmit data paths.
The receive path contains a Low-Noise Amplifier (LNA) with a bypass switch. The LNA impedance
matching networks are internal to the module and have been optimized for a low Noise Figure
(NF) while maintaining good return losses into a 50 Ω source and load impedance.
The transmit path contains a Power Amplifier (PA) optimized for saturated performance.
The PA output is internally matched for optimum output power and efficiency into a 50 Ω load
impedance, and passed through an harmonic filter before passing through the DPDT switch.
The PA input provides a good return loss into a 50 Ω source impedance.
The SKY65348 has a shutdown mode to minimize power consumption. All of the eight operating
modes are controlled through three digital input pins.
When the output power is 10mW, SKY65352 is applied as RF Power AMP(U13). When 0.5W,
SKY85348 is applied as AMP. L11 and L12 take a role of matching Zigbee Chip, LM2455(U11) to
RF power AMP(U13). When the power is 500mW, the feature of SKY65348 is as follows;
• Transmit output power >±27 dBm
• Receive path NF <3.1㏈
• Analog power control
• Integrated control logic
• LNA bypass mode
• Shutdown mode
• Small footprint, MCM (28-pin, 8 x 8 mm) package (MSL3, 260 C per JEDEC J-STD-020)
• Single DC supply = 3.3V