* Information for OEM integrator : The OEM integrator has to be aware not to provide information to the end user regarding how to install or
* Information for OEM integrator : The OEM integrator has to be aware not to provide information to the end user regarding how to install or remove this RF module in the user manual of the end product. remove this RF module in the user manual of the end product. The user manual which is provided by OEM integrators for end users must include the following information in a prominent location. d Th The user manual which is provided by OEM integrators for end users must include the following information in a prominent location. To comply with FCC RF exposure compliance requirements, the antenna used for this transmitter must be installed to provide a separation To comply with FCC RF exposure compliance requirements, the antenna used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be co-located or operating in conjunction with any other antenna or transmitter. distance of at least 20 cm from all persons and must not be co-located or operating in conjunction with any other antenna or transmitter. Label for end product must include Contains FCC ID: A3LWIDT20R/ IC ID:649E-WIDT20R or Label for end product must include Contains FCC ID: A3LWIDT20R/ IC ID:649E-WIDT20R or A RF transmitter inside, FCC ID: A3LWIDT20R/ IC ID:649E-WIDT20R. A RF transmitter inside, FCC ID: A3LWIDT20R/ IC ID:649E-WIDT20R. id d b OEM i l d th f l hi h i t l t i ti ti ll f t t f i i i i 1. Introduction 1. Introduction WIDT20R is a USB embedded module compliant with IEEE802.11n standard. The WIDT20R is a USB embedded module compliant with IEEE802.11n standard. The core chipset is from Ralink, part number is RT5572. core chipset is from Ralink, part number is RT5572. m 2. Hardware Architecture:
2. Hardware Architecture:
2.1 Main Chipset Information 2.1 Main Chipset Information
2.2 Circuit Block Diagram 2.2 Circuit Block Diagram g The major internal components and external interfaces of WIDT20R are illustrated in Figure 1-1. The major internal components and external interfaces of WIDT20R are illustrated in Figure 1-1. Figure 1-1 WIDT20R Major Component and System Interface Figure 1-1 WIDT20R Major Component and System Interface 3. Antennas Information Two SMD antennas supporting both TX & RX. Hz 4. Operational Description WIDT20R is the 802.11a/b/g/n RF Module, that acts as a communication hub for users of a wireless device to connect to a wired LAN. MIMO type Product type: WLAN (11b mode: 1TX, 1RX, 11g mode: 1TX, 1RX, n mode: 2TX, 2RX) Time base of the transmission frequency For IF and RF frequency, Crystal is a clock reference. Synthesizer Synthesizer inside Transceiver. Internal voltage controlled oscillator (VCO) provides the desired LO signal base on the phase-locked loop (PLL) with a relatively wide tuning range for this application. Transmission Base-band Processing (BBP) IC has DSSS (BPSK/QPSK/CCK) and OFDM
(BPSK/QPSK/16QAM/64QAM) modulation function, it provides transmission data rate are 1, 2, 5.5, 11 Mbps on DSSS and 6, 12, 18, 24, 36, 48, 54 Mbps on OFDM. Digital data signal will be converted to analog (TX IQ) signals through DAC in BBP IC, TX IQ pass through to low pass filter. TX I/Q signal use direct conversion (zero-IF) architecture converter to generate carrier frequency signal. Transceiver IC and internal PA magnify output power. Receiver Reverse direction isolation of LNA inside Transceiver IC suppresses unwanted radiation. Then RF signal will be directly down to IF signal (RX IQ) and high frequency spurious emissions are suppressed by LPF. At last RX IQ signal will be demodulated digital data. Base band Processing 1. Channel selection is controlled by BBP IC to support data modulation:
- DSSS (BPSK/QPSK/CCK)
- OFDM (BPSK/QPSK/16QAM/64QAM) Power Control Level It uses closed-loop power control function to limit RF output power level. Transmit/Receive Switch EUT has Transmit/Receive Switch and Antenna switch. End user cant select any power setting. Channel Selection Restriction For product available in the USA/Canada/Taiwan market, only channel 1~11 can be operated. Selection of other channels is not possible. But product also could be available in the Europe/Japan market, channel 1~13 can be operated under the manufacturer change the different driver. Data Rate Control The operation date rate is changing during data transfer base on the optimization of driver. Discontinue Transmitting with absence of Data or operational failure states The device shall automatically discontinue transmission in case of either absence of information to transmit or operational failure. These provisions are not intended to preclude the transmission of control or signaling information or the use of repetitive codes used by certain digital technologies to complete frame or burst intervals. Applicants shall include in their application for equipment authorization a description of how this requirement is met. Data transmission is always initiated by software, which is then passed down through the MAC, through the digital and analog baseband, and finally to the RF chip. Several special packets (ACKs, CTS, PSPoll, etc...) are initiated by the MAC. These are the only ways the digital baseband portion will turn on the RF transmitter, which it then turns off at the end of the packet. Therefore, the transmitter will be on only while one of the aforementioned packets is being transmitted. Product Details
> Modulation see the below table for draft n
> Data Modulation OFDM (BPSK / QPSK / 16QAM / 64QAM)
> Frequency : 2.4GHz and 5GHz
> Data Rate (Mbps) see the below table for Draft n
> Channel Number 4 for 20MHz bandwidth ; 2 for 40MHz bandwidth
> Channel Band Width (99%) MCS8 (20MHz): 18.08 MHz ; MCS8 (40MHz): 36.48 MHz Modulation modes