RF

Lower noise bandwidth

How To Achieve Good RF Sensitivity?

Introduce high gain in front of the receiver External LNA needed Poor linearity (IP3) Poor blocking/selectivity “Removes” the losses in the SAW filter     Lower noise bandwidth (narrowband) Blocking/linearity not changed Good selectivity Good frequency control needed

How Much Loss Can Have Between TX And RX

How Much Loss Can Have Between TX And RX?

Radio Range – Free Space Propagation Friis’ transmission equation for free space propagation: Pt is the transmitted power, Pr is the received power Gt is the transmitter; Gr is the receiver antenna gain Lambda is the wavelength D is the distance between transmitter and receiver or the range   120 dB link budgets at 433 […]

How To Increase The Range of RF System

How To Increase The Range of RF System

To increase the Range of RF System following 4 steps can be taken:- To increase the Output power Add an external Power Amplifier (PA) To increase the sensitivity Add an external Low Noise Amplifier (LNA) To increase both output power and sensitivity Add PA and LNA To use high gain antennas Regulatory requirements need to […]

Basic Building Blocks of an RF System

Basic Building Blocks of an RF System

Basic Building Blocks of the RF System is following:- RF-IC Transmitter Receiver Transceiver System-on-Chip (SoC); typically transceiver with integrated microcontroller Crystal Reference frequency for the LO and the carrier frequency Balun Balanced to unbalanced Converts a differential signal to a single-ended signal or vice versa Matching Filter Used if needed to pass regulatory requirements / […]

antennas

Antennas in RF System

Commonly used antennas are following:- PCB Antennas Little extra cost (PCB) Size demanding at low frequencies Good performance possible Complicated to make good designs Whip Antennas Expensive (unless piece of wire) Good performance Hard to fit in may applications Chip Antennas Expensive OK performance Antenna is very important if long range is essential. A quarter wave […]

Image rejection receiver

Crystals in RF System

Crystals provides reference frequency for Local Oscillator (LO) and the carrier frequency Various types Low Power crystals (32.768 kHz) Used with sleep modes on e.g. System-on-Chips Crystals Thru hole Tuning fork SMD Temperature Controlled Crystal Oscillators (TCXO) Temperature stability – some narrowband applications Voltage Controlled Crystal Oscillators (VCXO) Oven Controlled Crystal Oscillators (OCXO) Extremely stable

Super heterodyne receiver

Receiver Architecture in RF System

Super Heterodyne Receiver Super Heterodyne Receiver – e.g. CC1000 Converts the incoming signal to an Intermediate Frequency (IF) signal and performs: Carrier frequency tuning – selects desired signal Filtering – separates signal from other modulated signals picked up Amplification – compensates for transmission losses in the signal path Image Rejection Receiver Image Rejection Receiver – […]

Transmitter

Transmitter in RF System

Modern transmitters typically use fractional-N synthesizers For angle modulation like FSK, MSK, O-QPSK, the synthesizer frequency is adjusted For amplitude modulation like OOK and ASK, the amplifier level is adjusted

Full-duplex RF Systems

RF Communication Systems

Three RF Communication Systems Simplex RF System A radio technology that allows only one way communication from the transmitter to the receiver. Examples: FM radio, TV, One way AMR systems Half Duplex RF Systems Operation mode of the radio communication system in which each end can transmit and receive but not simultaneously. The communication is […]

The Electron in Atomic Structure

Since electronics deals with tiny particles called electrons, these small particles require detailed study. An electron is a negatively charged particle having negligible mass. Some of the important properties of an electron are: Charge on an electron, [pmath]e = 1.602*10^-19 [/pmath] coulomb Mass of an electron, [pmath]m = 9.0*10^-31[/pmath] Kg Radius of an electron, [pmath]r […]

What is RF and Microwave Radiation

What is RF and Microwave Radiation?

Radio Frequency (RF) technology plays important role in daily lives. RF (Radio Frequency) waves are used to communicate information from one place to another place through the air. RF technology is used in mobile communication, Radio and Radar, television broadcasts, satellite navigation and in international communication infrastructure. These high energy airborne waves are capable of […]

What Is RF

What Is RF?

RF is short for “Radio Frequency”. It is any frequency within the range of electromagnetic waves; these are related with radio wave propagation. When RF power is applied to an RF antenna, electromagnetic (EM) field is generated that is able to propagate in the space. This electromagnetic field is called “RF field” or “radio wave”. […]