1. Introduction This paper describes the LG AP circuits, specifications,layouts and partlist etc. 2. Circuit Description 2.1 The Architecture The radio design is centered on the expected signal characteristics of the modulation method. A Differential Quadrature Phase Shift Keying (DQPSK) modulation encodes the data in terms of phase with minimal amplitude variation, improving noise immunity.
Page 4
demodulation. The signal then goes to the high impedance input of the HFA3683 upconverting mixer for conversion to the 2.4GHz - 2.5GHz band. The mixer output goes to the pre-amplifier, in the HFA3683, amplifies the signal and easing the requirement for HFA3983 RFPA gain. FL2, a two pole dielectric bandpass filter, is used to suppress both transmit LO leakage and the undesired sideband.
Page 5
provides the optimum bias current temperature compensation when low TC external resistors are used. To get the best performance from the HFA3983, the output stage matching network can be tailored using external components. 2.4 2.4GHz RF/IF Converter and Synthesizer(HFA3683) The HFA3683A is a monolithic SiGe half duplex RF/IF transceiver designed to operate in the 2.4GHz ISM band.
Page 6
used as an input, taking the pad loss in consideration for evaluation, when using external VCO’s or generators, providing the on board VCO is disabled. A couple of power supply regulators have been added to improve the transmit and receive switching characteristics of the HFA3783.
Page 7
The HFA3861B transmitter is designed as a Direct Sequence Spread Spectrum Phase Shift Keying (DSSS PSK) modulator. It can handle data rates of up to 11Mbps (refer to AC and DC specifications). The various modes of the modulator are Differential Binary Phase Shift Keying (DBPSK) for 1Mbps, Differential Quaternary Phase Shift Keying (DQPSK) for 2Mbps, and Complementary Code Keying (CCK) for 5.5Mbps and 11Mbps.
Page 8
Spread Spectrum Modulator Description The modulator is designed to generate DBPSK, DQPSK, and CCK spread spectrum signals. The modulator is capable of automatically switching its rate where the preamble is DBPSK modulated, and the data and/or header are modulated differently. The modulator can support date rates of 1, 2, 5.5 and 11Mbps.
Page 9
2.9 Processor(MPC 860/855) The MPC860 PowerQUICC is a versatile one-chip integrated microprocessor and peripheral combination that can be used in a variety of controller applications, excelling particularly in communications and networking products. The PowerQUICC can be described as a next-generation MC68360 QUICC for network and data communication applications, providing higher performance in all areas of device operation including flexibility, extensions in capability, and integration.
Page 10
MPC860 SCC1 Port supports 10 Base-T Ethernet Interface at Access Point. MPC860 Enternet Controller needs external Seirial Interface Adaptor(SIA) and Transceiver, LW1100AP used LXT905LC device of LEVEL-ONE®. The LXT905 Universal 10BASE-T Transceiver is designed for IEEE 802.3 Physical Layer (PHY) applications.
3. Specifications 3.1 General Specification Item Specification Unit Comments Frequency Range 2400 ~ 2483.5 Radio Type Direct Sequence BPSK 1 Mbps Type of Modulation QPSK 2 Mbps Mbps CCK 5.5 and 11 Mbps 3.2 Electrical Specification Item Specification Unit Comment Output Power @ +2/-4 dB dBc min...
4. Block Diagram 4.1 Digital Board MPC855/860 DS1834A HRESET Software Reset Port D[7] Port D[9] Fail LED SDRAM Control GPL0/1/2/3 SDRAM RF Module 3.3V 11bit 32bit PCMCIA Data Bus 4/16/32Mbyte Interface Interface Bus Regulator 5~24V/1.5A MIC5206- 8bit Flash ROM 3.3BU Address Bus 21bit 512K...