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/:P2/:RF/:SDR RECEIVER

Software-Defined Radio Receiver

RTL-SDR frontend with a custom wideband low-noise amplifier (0.5–1800 MHz), SAW bandpass filters, and a Python demodulation pipeline with GNU Radio integration.

Project Duration 2 months
Status Completed
Year 2024
01

Bill of Materials

Component Part Number Quantity Notes
LNA MMIC BGA2803 1 0.9 dB NF, 21 dB gain
RF Switch PE4259 1 SPDT, <0.4 dB insertion loss
PCB Substrate RO4003C 1 Rogers, Dk=3.55
RTL-SDR R820T2 1 100 kHz - 1.75 GHz
SAW Filters Various 3 SW, VHF, UHF bands
02

Tools Used

GNU Radio
Signal processing framework for SDR demodulation
Python
rtlsdr bindings, numpy FFT waterfall display
KiCad
PCB design with controlled impedance traces
Raspberry Pi 4
GPIO control for RF switch
03

Diagrams & Schematics

Block Diagram
System block diagram showing signal flow
PCB Layout
PCB layout with coplanar waveguide traces
04

Assembly Process

1

PCB Fabrication

Designed and fabricated the LNA PCB using Rogers RO4003C substrate for optimal RF performance at microwave frequencies.

2

Component Assembly

Soldered the BGA2803 MMIC and PE4259 RF switch with careful attention to thermal management and RF grounding.

3

Filter Integration

Integrated three SAW bandpass filters covering shortwave, VHF, and UHF frequency ranges.

4

Software Setup

Configured Raspberry Pi GPIO for filter switching and set up GNU Radio flowgraphs for various demodulation modes.

05

Oscilloscope Analysis

LNA Gain
LNA Gain Response
Measured 21 dB gain across 100 MHz–2 GHz with 0.9 dB noise figure.
Filter Response
SAW Filter Response
Filter bandpass characteristics for SW, VHF, and UHF bands.
06

Resources & References

GNU Radio Documentation

Official documentation for GNU Radio signal processing framework.

RTL-SDR Project

Community resources and documentation for RTL-SDR hardware.