2.4-GHZ RF TRANSCEIVER FOR IEEE B WIRELESS LAN UF# UF#
Objective: Design of a system level 2.4 GHz RF- transceiver for wireless LAN Design of a system level 2.4 GHz RF- transceiver for wireless LAN Software used: Software used: Ansoft Ansoft Syscal Syscal MatLab MatLab
IEEE b Specifications Receiver: Receiver: Frequency range: 2.4 – GHz Frequency range: 2.4 – GHz Bit Rate: 1/2/5.5/11 Mb/s Bit Rate: 1/2/5.5/11 Mb/s BW: 22 MHz BW: 22 MHz Sensitivity: -80/-76 dBm Sensitivity: -80/-76 dBm FER: 8% FER: 8% Adjacent channel Rej: 41 dB Adjacent channel Rej: 41 dB Max Power level: -15 dBm Max Power level: -15 dBm Receiver NF: 8.3 dB Receiver NF: 8.3 dB
Transmitter: Transmitter: Max transmit power: 30 dBm Max transmit power: 30 dBm Transmit Spectrum mask Transmit Spectrum mask f c = 0 dBr f c = 0 dBr f c -22MHz <f < f c -11MHz -30 dBr f c -22MHz <f < f c -11MHz -30 dBr f c - 11MHz < f < f c +22MHz -30 dBr f c - 11MHz < f < f c +22MHz -30 dBr f < fc-22MHz -50 dBr f < fc-22MHz -50 dBr f > fc+22MHz -50 dBr f > fc+22MHz -50 dBr Center frequency tolerance:+/- 25 MHz Center frequency tolerance:+/- 25 MHz
Transmitter Architecture
Transmitter Specifications: a) o/p power spectrum : -15 dBm b) 11 Mb/s CCK modulation c) 1 Mb/s Data rate d) Barker Code:
Specification of parts used in TX IF Mixer: IF Mixer: AD8343 AD8343 Conversion Gain: 7.1 dB Conversion Gain: 7.1 dB Input IP3: 16.5 dBm Input IP3: 16.5 dBm LO power: 20 dbm LO power: 20 dbm Noise Figure: 14.1 dB Noise Figure: 14.1 dB Input P1 dB: 2.8 dB Input P1 dB: 2.8 dB IF-SAW filter IF-SAW filter : : Center Frequency: 300 MHz. Stopband Rejection: 53 dB. Insertion Loss: 4.5 dB
RF Mixer: RF Mixer: HMC400MS8 HMC400MS8 Conversion Loss: 8.8 dB Conversion Loss: 8.8 dB Input IP3: 35 dBm Input IP3: 35 dBm LO power: 18 dBm LO power: 18 dBm Noise Figure: 8.8 Noise Figure: 8.8 Input P1 dB: 22 dBm Input P1 dB: 22 dBm RF- Band Pass Filter: RF- Band Pass Filter: Insertion Loss: 1.1 dB Insertion Loss: 1.1 dB Center Frequency: 2400 MHz. Center Frequency: 2400 MHz. Attenuation at cutoff frequencies: 50 dB Attenuation at cutoff frequencies: 50 dB Power amplifiers: HMC287MS8 HMC287MS8 Gain: 21 dB Gain: 21 dB Noise Figure: 2.2 dB Noise Figure: 2.2 dB OP3: 7 dBm OP3: 7 dBm OP1: 3 dBm OP1: 3 dBm GBH120_214 GBH120_214 Gain: 18 dB Gain: 18 dB IP3: 33 dBm IP3: 33 dBm Noise Figure: 4.5 dB Noise Figure: 4.5 dB
Transmit Spectrum
Constellation at TX Output
Receiver Architecture
Specifications of the parts used in RX RF- Band Pass Filter RF- Band Pass Filter : : Insertion Loss: 1.1 dB Insertion Loss: 1.1 dB Center Frequency: 2400 MHz. Center Frequency: 2400 MHz. Attenuation at cutoff frequencies: 50 dB Attenuation at cutoff frequencies: 50 dB Mixer Mixer HMC400MS8 HMC400MS8 Conversion Loss: 8.8 dB Conversion Loss: 8.8 dB Input IP3: 35 dBm Input IP3: 35 dBm LO power: 18 dBm LO power: 18 dBm Noise Figure: 8.8 Noise Figure: 8.8 Input P1 dB: 22 dBm Input P1 dB: 22 dBm LNA HMC287MS8 HMC287MS8 Gain: 21 dB Noise Figure: 2.2 dB OP3: 7 dBm OP1: 3 dBm IF-SAW filter : Center Frequency: 300 MHz. Stopband Rejection: 53 dB. Insertion Loss: 4.5 dB
AD8343 AD8343 Conversion Gain: 7.1 dB Conversion Gain: 7.1 dB Input IP3: 16.5 dBm Input IP3: 16.5 dBm LO power: 20 dbm LO power: 20 dbm Noise Figure: 14.1 dB Noise Figure: 14.1 dB Input P1 dB: 2.8 dB Input P1 dB: 2.8 dB Low Pass Filter Low Pass Filter Insertion Loss: 3 dB Insertion Loss: 3 dB Pass band: 0-18 MHz Pass band: 0-18 MHz Rejection: 50 dB Rejection: 50 dB Stop band: 19.1 to 100 MHz. Stop band: 19.1 to 100 MHz. VSWR: 1.5:1 VSWR: 1.5:1
Receiver Requirements SNR SNR FER = 8 Frame = 1024 8 bits FER = 8 Frame = 1024 8 bits Let F be the probability that a frame is received correctly, F100 = 0.92 Let (1-P) be the probability a bit is in error P1024*8 = F P = 0.92(1/ (1024*8*100)) 1-P = 1.01 10-7 Therefore, BER = 1.01 10-7 E/N = (erfinv (1-2*BER)) ^2 E/N = 13.5 dB S/N = S/N = 10.5 dB Adhering to a stricter margin, the S/N can be decided to be 12.3 dB
Noise Figure Noise Figure Sensitivity = NF + SNR + Noise Floor. -80 = ×log (22×106) +12+NF NF = 8.3 dB The noise figure of the receiver should be <= 8.3 dB. IIP3 IIP3 Adjacent channel carrier power= sensitivity+41 dB Carrier power of channel of interest = sensitivity+6 dB Therefore the MDS (minimum discernable signal) is –80+6-SNR= = = Carrier power of adjacent channel = = -39 IIP3 = (-39-(-84.5))/2 = Therefore IIP3 for a receiver should be higher than –16.25.
Link Budget Analysis (Syscal)
IIP3 IIP3 From the previous figure, we find the IIP3 of the receiver to be dBm, which is > dBm From the previous figure, we find the IIP3 of the receiver to be dBm, which is > dBm Noise Figure Noise Figure The NF of the receiver system is 8.46 dB The NF of the receiver system is 8.46 dB
Variation of parameters with probe location
Summary-Transceiver Specifications Heterodyne Architecture: Heterodyne Architecture: IF=300 MHz, RF=2.4 GHz IF=300 MHz, RF=2.4 GHz Transmitter Specifications Transmitter Specifications Data Rate = 1 Mb/s interleaved on 11 Mb/s Barker Code Data Rate = 1 Mb/s interleaved on 11 Mb/s Barker Code O/P Power = -15 dBm O/P Power = -15 dBm Receiver Specifications Receiver Specifications Noise Figure = 8.46 dB Noise Figure = 8.46 dB Gain = Gain = OIP3 = 4.07 dBm OIP3 = 4.07 dBm Min SNR = 12.3 Min SNR = 12.3