Tag Archives: RF

Arduino weather station with RF433 MHz modules


by eliesalame @ instructables.com:

In this project I will show you how make two Arduinos talk to each other using RF frequency (wireless).

Now I will use the knowledge in all these project and improve on them by making one Arduino send data to another Arduino wirelessly using an RF433 module and displaying it on I2C serial LCD.

Arduino weather station with RF433 MHz modules – [Link]

8V97051 Low Power Wideband Fractional RF Synthesizer

This design features a low power wideband RF synthesizer that is used in GSM receiver cards. It has dual differential and open drain outputs with frequency range of 34.375MHz to 4400MHz(in continuous range). The logic compatibility is 1.8V while the system is running on a single 3.3V supply. It has -143dBc/Hz Phase Noise (PN) performance at 1MHz Offset for every 1.1GHz output. It is also capable of mute function at RF_OUT that is accessible via mute pin or SPI command. It is low power with only 380mW average power consumption while RF_OUTB is not in used.

The design is comprised of 3 major parts. The first part consists of IDT8V97051NLGi wideband RF synthesizer/PLL supports the output frequencies with Voltage Controlled Oscillator (VCO). The temperature compensated crystal oscillator close to the RF input helps in the precision of signal while the other parts are filters that are used in various purposes like minimizing undesired noise. The second part consists of the USB 2.0 high speed to UART/FIFO IC that is used for system interface while the I2C-bus to SPI bridge IC controls the sequences, protocol, and timing of the signal. The last part is power supply management of the system in which it is provided with RC filters in every line to ensure minimal noise are included in the supply.

The design is applicable in multi-carrier, multi-mode Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD) base station radio card. It optimizes multi-service base stations during its service as a local oscillator that generates a large variety of frequencies to mixers while maintaining excellent PN.

8V97051 Low Power Wideband Fractional RF Synthesizer – [Link]



Sinewave Generator


Sine wave Generator project will provide you with a Sinusoidal Waveform output to test various instruments.  You can also use the High quality output from this kit to insert a tone modulation in your audio and RF equipment.  This kit is designed using XR2206 IC to provide High Stability and Accuracy.

  • Supply input 12 VDC Max @ 50 mA
  •  Range: Jumper selectable and preset tunable range of 10 Hz – 100 KHz
  •  Output Level can be controller with onboard preset
  •  Power-On LED indicator
  •  Screw terminal connector for easy connection
  •  PCB dimensions 55 mm x 50 mm

Sinewave Generator – [Link]

High Reliability, High Isolation Single-Pole-Double-Throw RF switch

In telecommunications, ideal RF switches require low insertion loss, high isolation and linearity. The IDT F2912 is a single-pole-double throw RF switch capable of having low insertion of loss of 0.4dB at 1GHz and a RF1 to RF2 Isolation of 74dB at 1GHz with extended temperature of -55C to +125C making it highly reliable. In addition, this covers a broad frequency range from 300kHz to 8000MHz.

As a switch, it’s capable of 3 types of controls namely switch control, mode control, and logic control. The switch control includes (3 states and 2-pin control input) or (2 states and 1-pin control input). The 3 states and 2-pin control input operates like a XOR logic gate, if there is a high value input from the control pin either CTL1/CTL2 will trigger RF1 to RF Com if CTL1 is High or RF2 to RF Com if CTL2 is High. While the 2 states and 1-pin control input, a high value CTL2 will trigger RF2 to RF com and a low value CTL2 triggers RF1 to RF Com leaving the CTL1 a “don’t care”. The mode control use either (2-pi

n control: CTL1 and CTL2) or (1-pin control: CTL2). When RF1 and RF2 ports are both open (State 1), all 3 RF ports are terminated to an internal 50Ω termination resistor. When RF1 or RF2 port is open (State 2 or State 3 OFF condition), the open port is connected to an internal 50Ω termination resistor. When RF1 or RF2 port is closed (State 2 or State 3 ON condition), the closed port is connected to the RF Com port. The logic control operates using logic voltage 1.8V and 3.3V to operate logic CTL (pin18) VCC and GND respectively.

This circuit design can be applied more on base station 2G, 3G, 4G, portable wireless, repeaters and E911 systems, digital pre-distortion point to point infrastructure, public safety infrastructure WIMAX receivers and transmitters, military systems, JTRS radios, RFID handheld and portable readers, cable Infrastructure, wireless LAN, test/ ATE Equipment.

High Reliability, High Isolation Single-Pole-Double-Throw RF switch – [Link]

VHF-UHF RF Sniffer


by simpletronic @ instructables.com

This is a multi-chapter instructable. I will be describing the making of a short/medium range RF remote-control using the UHF 433Mhz frequency. It´s impossible to setup & adjust a RF transmit-receive link if you are not sure the transmitter is working properly.At 433MHz, your multimeter or even a regular oscilloscope are totally useless.

VHF-UHF RF Sniffer – [Link]

The Simple Scalar Network Analyzer


by rheslip.blogspot.com:

After playing around with the SynthNV signal generator/power detector discussed in the previous post I realized what a useful a tool it is for RF testing. While its a terrific tool for VHF/UHF/Microwave testing, the SynthNV has a couple of serious limitations for amateur use in the HF region – the signal generator has a minimum frequency of 35 MHz, the generated signal has a lot of harmonics and its a fairly expensive piece of gear. This project is a fairly simple, very low cost Scalar Network Analyzer that does the same thing in the HF bands from 1MHz to 30MHz. If you buy the parts from China or Ebay and do some scrounging it should cost you less than $20 to build.

The Simple Scalar Network Analyzer – [Link]

RFM69HCW transceiver can go up to 20dBm


This powerful RF transceiver is also highly secure thanks to a HW support of CRC-16 and AES-128.

The RFM69HCW is a highly integrated RF transceiver capable of operation over a wide frequency range, including the 433, 868 and 915 MHz license-free ISM (Industry Scientific and Medical) frequency bands. Its highly integrated architecture allows for a minimum of external components whilst maintaining maximum design flexibility.All major RF communication parameters are programmable and most of them can be dynamically set. The RFM69HW offers the unique advantage of programmable narrow-band and wide-band communication modes without the need to modify external components. The RFM69HW is optimized for low power consumption while offering high RF output power and channelized operation. TrueRF™ technology enables a low- cost external component count (elimination of the SAW filter) whilst still satisfying ETSI and FCC regulations.

On stock we also keep a less powerful version – RFM69CW, suitable for all applications where a lower range is sufficient.

RFM69HCW transceiver can go up to 20dBm – [Link]

Visualizing RF Standing Waves on Transmission Lines

This video illustrates how RF (radio frequency) standing waves are created in transmission lines – through the addition of the forward (transmitted) wave and the reflected wave that results from improperly terminating the line or matching the load or antenna to the transmission line impedance. I have done several videos that relate to transmission lines, terminations and reflections – all of which tell a piece of the story. This video is another piece, and I hope it helps you to understand how standing waves are formed and what the “look” like.

Visualizing RF Standing Waves on Transmission Lines – [Link]