Submitted By:-

Bhaskar Jyoti DekarajaJanmoni MedhiSujita BorahTridib Sharma

Transmitter and Receiver pair using Radio

Frequency 434MHz

Introduction on Radio Frequency

It is the rate of oscillation in the range of 30 KHz-300 GHz.

It has the ability to flow through path containing capacitor and inductor.

RF current can usually ionize air creating conductive path.

To receive a radio signal antennae is used.

When conducted by an ordinary electric cable, RF current reflects and travel back towards the

source. This condition is called Standing Wave.

RF must be passed through transmission lines .

RF current does not penetrate deeply into electrical conductors but tends to slow along the

surface. This is known as Skin Effect.

CIRCUIT DIAGRAM

RF Transmitter

A radio transmitter is an electronic device which, when connected to an antenna, produces

an electromagnetic signal such as in radio and television broadcasting, two way communications or radar

The radio transmitter is comprised of an information signal, oscillator, and modulator.

An LC Oscillator is a simple implementation for an oscillator, and can be used with a modulator to

modulate information signal with the oscillator and carry it to the antenna where it can broadcasted.

The antenna transfers the radio signal to a tuner which utilizes a bandpass filter that has a high gain in the

band pass and a low gain at all other frequencies to suppress all other frequencies except the desired

frequency that contains information.

RF Receiver

Radio receiver design includes the electronic design of different components of a radio receiver

which processes the radio frequency signal from an antenna

The receiver picks up the transmitted signals using the 434Mhz receiver module.

The receiver and transmitter must have same tuned frequency.

PIN diagram of Encoder and Decoder

Fig.:-Encoder Fig.:-

Decoder

PIN Description of Encoder

PIN Description of Decoder

HT12E Encoder and decoder

It is an encoder IC of 2^12 series of

encoders.

Mainly used in interfacing RF and

Infrared circuits.

Encoders and decoders should have

same no of address and data format.

Converts the parallel input’s into serial

output.

HT12D is a decoder integrated circuit

that belongs to 2^12 series of decoders.

This series of decoders are mainly used

for remote control system applications,

like burglar alarm, car door controller,

security system etc.

HT12D converts the serial input into

parallel outputs.

What we have done till now

Connected the RF modules (434MHz) in respective Transmitter and Receiver named Bread Board circuit.

Connected the Encoder (HT12E) and Decoder (HT12D) in respective Transmitter and Receiver named Bread Board circuit respectively.

  Connected the Push buttons after finding its positive

and negative terminals in the Transmitter Circuit breadboard.

  Connected the LEDs after finding its positive and

negative terminals in the Receiver Circuit breadboard.

  Given all the address ports of Encoder and Decoder

‘0’ (Grounded) input so as to match the data of transmitter and receiver.

  Made the jumper connections in the bread board so

as to nullify the connection problems. 

Connected the resistors as per the circuit diagram in the encoder and decoder.

Given No Connection as per the circuit diagram.  Connected the Antennas in the Transmitter and Receiver

pair for the transmission via Radio Frequency. 

And finally given the Power Supply of 5 Volt. For the functioning of the Transmitter and Receiver pair successfully.

A fluctuation across the terminals of the LEDs are observed when switches are turned on and off.

Transmitter part

Receiver part

Thank You