แสดงบทความที่มีป้ายกำกับ RF แสดงบทความทั้งหมด
แสดงบทความที่มีป้ายกำกับ RF แสดงบทความทั้งหมด

Xbee Wireless Kit (Chip Antenna)

This is a complete XBee wireless communication kit with everything you need to get up and running quickly, including 2 1mW XBee modules with chip antenna, the popular USB XBee Explorer, an XBee shield as well as headers required for the XBee shield. The very popular 2.4GHz XBee modules from Digi (formally Maxstream) take the 802.15.4 stack (the basis for Zigbee) and wrap it into a very simple to use serial command set. These modules allow a very reliable and simple communication between microcontrollers, computers, systems, really anything with a serial port! Point to point and multi-point networks are supported.
 The goal for this complete XBee Kit is to make wireless communication simple. Connect one XBee to the shield and your Arduino, connect the other XBee to the Explorer board and your computer, and you'll be able to seamlessly pass serial data to and from your Arduino wirelessly! Using this connection, you can transmit remote sensor data, or send data from your computer to update a scoreboard, or drive a robot from your keyboard! [...] Read more

AM portable radio receiver by ZN414 IC




An AM portable radio receiver made from the ZN414 IC. The ZN414 ic has now been replaced by the MK484 which is identical in performance and pinout.

Read More

Micro Power AM Broadcast Transmitter

In this circuit, a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a class C amplifier configuration. The oscillator frequency can be either fixed by a crystal or made adjustable (VFO) with a capacitor/resistor combination. A 100pF capacitor is used in place of the crystal for VFO operation. Amplitude modulation is accomplished with a second transistor that controls the DC voltage to the output stage.


Read more

Antenna tuning pdf file

Antenna tuning pdf file

Source : http://www.educypedia.be/electronics/antennawifi.htm

Antennas & Transmission Lines

Antennas & Transmission Lines omnidirectional antenna, biquad antenna, cantenne, horn antenna, Yagi Antenna, pdf file

Source : http://www.educypedia.be/electronics/antennawifi.htm

Antennas for 2.4 GHz WiFi

Antennas for 2.4 GHz WiFi wide angle antenna for 2.4 GHz WiFi, sector antenna for 2.4 GHz WiFi, Modified 3D Corner Reflector Feed for SAT TV offset parabolic dish, 2 el. BiQuad Feed for Offset Dish at 2.4 GHz WiFi, ...

Link : Antennas for 2.4 GHz WiFi

Antennetechniek voor WISPs

Antennetechniek voor WISPs biquad, cantenne, Biloop antenne

Source : http://www.educypedia.be/electronics/antennawifi.htm

Antenna construction

Antenna construction Quarter wave omnidirectional antenna for 2.4 GHz, omnidirectional antenna, Omnidirectional collinear antenna for 2.4 GHz, Biquad antenna for 2.4 GHz, Biquad antenna as a 2.4 GHz feeder for a Parabolic Dish, Can antenna for 2.4 GHz, pdf file

Source : http://www.educypedia.be/electronics/antennawifi.htm

Antenna Basics

Antenna Basics 1/4 Wavelength Ground Plane, Yagi antenna, horn antenna, Parabolic Dish, focus f = D2/16.c ; D= diameter of the parabola, c is depth of the parabola, BiQuad antenna, pdf file

Source : http://www.educypedia.be/electronics/antennawifi.htm

802.11 Wireless LAN Cards

802.11 Wireless LAN Cards schematics

Source : http://www.educypedia.be/electronics/antennawifi.htm

2.4 GHz WLAN Radio Interface

2.4 GHz WLAN Radio Interface IEEE 802.11b radio interface, Radio signal propagation at 2.4 GHz, Link budget calculations, pdf file

Source : http://www.educypedia.be/electronics/antennawifi.htm

2.45 GHz power amplifier with the BFG480W

2.45 GHz power amplifier with the BFG480W At a frequency of 2.45 GHz, a supply voltage of 3.0 V, and a control voltage of 3.0 V, the amplifier delivers an output power of 19 dBm at an input power of 8 dBm, with a power added efficiency of 38 %, pdf file

Source : http://www.educypedia.be/electronics/antennawifi.htm

2.4 GHz low noise amplifier with the BFG480W

2.4 GHz low noise amplifier with the BFG480W This application note gives an example of a 2.4 GHz LNA with the BFG480W. Because this LNA design has a high third order intercept value of 17 dBm (measured at input), it can be used for Wireless Local Area Network (WLAN) front-end and Wireless Local Loop (WLL) applications, pdf file

Soruce : http://www.educypedia.be/electronics/antennawifi.htm

2.4GHz AntennaAlignement

2.4GHz AntennaAlignement This paper attempts to provide some insight into the nature of radio propagation in that part of the spectrum (upper VHF to microwave) used by experimenters for high-speed digital transmission. It begins with the basics of free space path loss calculations, and then considers the effects of refraction, diffraction and reflections on the path loss of Line of Sight (LOS) links

Source : http://www.educypedia.be/electronics/antennawifi.htm

How to buy Motorola Talkabout T9500 2-Way Radio


The Motorola® I9550 Camo 25 Mile two-way radio is ready for your long distance communication needs. The unit is iVOX enabled for easy to use, hands-free communication without the need for an audio accessory. The NOAA Weather Alert Radio provides you...

Morse Code Practice Oscillator

This simple code practice oscillator project for beginners to Continuous Wave Morse Code uses a 555 timer to generate a dit or dah sound when the key is pressed.

Good Link
More circuit by IC 555
More about Oscillator Generator
More about Squarewave Oscillator circuit



Read link : http://www.electronics-project-design.com/CodePracticeOscillator.html

Ham Radio Circuit - Morse Code Filter Project

This project will help to filter out the interference signal and ensure that the signal received from the Morse code station stand out.

Read more : http://www.electronics-project-design.com/HamRadioCircuit.html

Active FM Antenna Amplifier (link)

2SC2570 Active FM Antenna Amplifier (link)

Alternating On-Off Switch, #2(link)

Alternating On-Off Switch, #2(link)
This circuit is the transistor version of the 4069 cmos type. Every press of the push-button will activate or de-activate the relay.

VHF-HF TRANSVERTER

This little circuit is a transmitting and receiving converter (transverter) that converts a FT290 or similar multimode handheld transciever to the 14MHz amateur band. The project is a single board module that needs an external local oscillator, for example, the VHF harmonic oscillator (or QRP VHF FM TX) LO for transverter project. It should be a relatively simple matter of scaling coils and caps to convert other bands. You may choose to omit the TX/RX switching and the TX mixer and use this unit as a receive converter giving 14MHz - 16MHz coverage on a multimode VHF receiver.

If you choose to use the full transverter circuit then you will be pleasantly surprised at the spectral purity of the transmitted signals. All unwanted spurious signals and even oscillator breakthrough are well under -75dB at the output terminal. The HF TX output from the unit is about 2mW and will give a full ten watts from my 10-Watt HF linear amplifier. The VHF rig must be of the type that also delivers +10v DC at the antenna socket on transmit. This is true of the FT290, C58 and most multimode handportables.

Read More
http://web.telia.com/~u85920178/conv/conv-00.htm

Electronic projects circuits