P O 2.4GH RFT : Resentation N Z Ransceiver
P O 2.4GH RFT : Resentation N Z Ransceiver
P O 2.4GH RFT : Resentation N Z Ransceiver
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CONTENTS
Receiver Blocks (Details and Schematics) Receiver Schematic Receiver Waveforms Transmitter Blocks (Details and Schematics) Transmitter Schematic
Transmitter Waveforms
LNA DESIGN
A 2.4GHz LNA utilizing a cascode technique and a simple LC matching network is designed. LNA is the first level of the active receiver circuit; its performance is good or bad has a great impact on overall performance of the receiver. Negative feedback source inductance common source low noise amplifier (CS-LNA) because of its noise performance has been widely used.
Input matching network is designed using a simple LC network including external inductors and the transistor gate-source capacitor (Cgs) matched to 50 Ohms
Following are the simulation Results in Cadence S21 13.38 dB Noise Figure - 1.48 dB IIP3 (13.47dBm:-8.8dBr
LNA SCHEMATIC
MIXER DESIGN
A Gilbert Cell utilizing CMOS 180nm technology is designed Following are the frequencies that are chosen. A low pass RC filter is connected at the IF differential outputs. RF = 2.4GHz, LO = 2.5GHz, IF = 100MHz
Follow are the simulation results that are observed A conversion gain of 12.1dB is achieved [based on the transient response low pass output is 808mV while the RF input is 200mV. Conversion gain is 20*log (VIF/VRF)] A noise figure of 13.6dB at 100MHz (IF freq) is observed S-parameters are plotted (S22<-30dB, S11<-10dB, S13<-50dB, S31<-30db, S32<-20dB, S23<-20dB) where RF is port1, IF is port2 and LO is port3
MIXER SCHEMATIC
VCO DESIGN
A 2.4GHz VCO is designed utilizing a PMOS differential pair on the top of a NMOS cross coupled pair. Tuning is achieved using PMOS based transistor varactors. Following are the simulations results in Cadence Transient Analysis Frequency of the two differential outputs O1 and O2 is 2.39GHz
A phase noise of -95.28dBc/Hz is observed at 102.92 KHz offset and a phase noise of 131.63 dBc/Hz is observed at 3.14 MHz
VCO SCHEMATIC
RECEIVER
RECEIVER DESIGN
The single ended output from the LNA is converted to differential using a balun The differential Outputs from the VCO are connected to the LO+ve and LO-ve terminals of the mixer A low pass filter with a cut off frequency of 318MHz is connected at the differential ouputs Following are the frequencies that are chosen. A low pass RC filter is connected at the IF differential outputs. RF = 2.4GHz, LO = 2.3GHz, IF = 100MHz Following are the simulations results (Transient Analysis) in Cadence LNA Output 110mVpp, 2.4GHz VCO Output frequency 2.27GHz Mixer IF Outputs 0.85Vpp, 130MHz
RECEIVER SCHEMATIC
LNA Mixer VCO
110mVpp, 2.4GHz
RF+ve
RF-ve
0.85Vpp 130MHz
IF1 - IF2
RF
LO
IF
TRANSMITTER
TRANSMITTER DESIGN
The output of the mixer is connected to the Class A power amplifier The differential Outputs from the VCO are connected to the LO+ve and LO-ve terminals of the mixer Following are the frequencies that are chosen. RF = 2.4GHz, LO = 2.3GHz, IF = 100MHz Following are the simulations results (Transient Analysis) in Cadence IF inputs 0.5Vpp, 100MHz VCO Output frequency 2.3GHz Power Amplifier Output 2.35Vpp, 2.4GHz
TRANSMITTER SCHEMATIC
VCO Mixer Class A PA
Filter
IF+ve
IF-ve
2.3GHz
MIXER OUTPUT
QUESTIONS ???
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