Input filter prevents instrumentation-amp RF-rectification errors -  11/13/03  EDN Design Ideas:  instrumentation amplifiers serve in a variety of applications that need to extract a weak differential signal from large common-mode noise or interference.  However, designers often overlook the potential problem of RF rectification Design by Charles Kitchin, Lew Counts, and Moshe Gerstenhaber, Analog Devices, Wilmington, MA

Low Cost Coupling Methods for RF Power Detectors replace Directional Couplers -  AN91 AN91 describes an RF feedback coupling method which eliminates the directional coupler.  instead, a 0.4pF ±0.05pF capacitor and 50Ω resistor are used to feed RF signal back to the LTC power controller.  This method reduces coupling loss variations, cost and lead time.  __ Linear Technology/Analog Devices

Low-cost RF sniffer finds 2.4-GHz sources -  11/23/06 EDN Design Ideas:  Locate interference sources in the iSM band Design by Vladimir Dvorkin, Linear Technology Corp, Milpitas, CA

Medium range transmitter -  This is a medium range transmitter circuit diagram.  This is also improved by changing the values of the resistor __ Contact Ashad Mustufa

Microwaves & RF Magazine Cover Feature: CEL & eRide Team to Provide Embedded GPS Solution  -  App Note  Doc #913__ California Eastern Laboratories

Odd-order Diode Multiplier -  The purpose of the circuit is to take advantage of the superior noise and switching characteristics of Schottky barrier diodes to make a high performance odd-order frequency multiplier.  Modern quartz oscillators have reached a level of performance where it has become difficult to multiply the fundamental frequency without degrading the phase noise by more than the unavoidable 20 dB per decade of multiplication.  Thanks to the Schottky barrier diode's extremely low flicker noise, this circuit adds little excess noise __  Reprint courtesy of RF Design Magazine

One W Experimental Output & One Meter Loop Antenna for 187 kHz (Lowfer) -  A pair of bipolar transistors makes a 1 watt output stage that drives a 1 square meter loop antenna.   __ Designed by Dick Cappels

PIC16F84 RF remote Controller -  With a handful of inexpensive components, a little creativity, and the power of PicBasic, you can build some pretty outstanding robotics creations as Rob Arnold proves with his Ruf-Bot project.   __ Designed by Rob Arnold

Popcorn direct Conversion receiver -  schematic for a no-frills, relatively low-cost CW superhet receiver with a 4.00 MHz intermediate frequency.  There is no AGC or RF gain control, however this receiver has good large signal handling capability.  This receiver uses just 6 bipolar transistors and an op amp for reasonable volume into headphones.  Much__ 

Precision 300MHzto 7GHz RF Detector with Gain & Offset Adjustment -  LTC5509__ Linear Technology/Analog Devices

Precision 300MHzto 7GHz RF Detector with Shutdown & Gain Adjustment -  LTC5530__ Linear Technology/Analog Devices

Precision 600 MHz to 7GHz RF Detector with Adjustable Gain & 12MHz Baseband Bandwidth -  LT5534__ Linear Technology/Analog Devices

ProgrAmpredicts VSWR-mismatch RF uncertainties -  02/01/01 EDN Design Ideas:  Hewlett-Packard (now Agilent Technologies] once offered a useful little cardboard slide rule for calculating the uncertainty in RF  measurements stemming Design by Steve Hageman, Agilent Technologies, Santa Rosa, CA

R/C Battery Backup -  Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

R/C Pilot -  Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

R/C Switch -  This circuit is a so-called "Radio controlled Electronic Switch".  it can be used to switch on/off anything electrical, whatever it is.  Here are a couple of examples: navigation lights, landing gear, sound systems, Glowplug driver, bomb release, parachute, search lights, gyros, and so on.  This circuits connects to a RC car controller servo output.   __ Designed by Tony van Roon  VA3AVR

R/C Switch 2 -  Circuit (Adjustable, 20-80 seconds) + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

R/C Switch 3 -  Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

R/C Switch 4 -  Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

R/C Switch 5 -  Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

Radio Controlled Battery Backup -  Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

Radio Controlled Pilot -  Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

Radio Controlled Switch -  This circuit is a so-called "Radio controlled Electronic Switch".  it can be used to switch on/off anything electrical, whatever it is.  Here are a couple of examples: navigation lights, landing gear, sound systems, Glowplug driver, bomb release, parachute, search lights, gyros, and so on.  This circuits connects to a RC car controller servo output.   __ Designed by Tony van Roon  VA3AVR

Radio Controlled Switch 2 -  Circuit (Adjustable, 20-80 seconds) + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

Radio Controlled Switch 3 -  Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

Radio Controlled Switch 4 -  Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

Radio Controlled Switch 5 -  Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

Receiver (Rx) Regulator -  Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

Reduce Component Count & Improve Efficiency in SLIC & RF Power Supplies -  DN282 Design Notes__ Linear Technology/Analog Devices

RF 2.45Ghz Signal Detector -  This passive RF indicator is made from a few simple parts.  A 100uA moving coil meter is used to display the relative intensity of the RF signal.  This circuit can be used with some cell phones and many cordless telephones . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

RF Actuated CW Monitor -  amateur radio construction projects.   __ Designed by Peter Parker

RF Detectors, level meters, attenuators, dummy loads, Signal dividers -  several circuits on this page.   __ Designed by Jan-Martin Nøding

RF Dummy Load -  make this simple RF Dummy Load for off-air testing of your radio transmitter__ 

RF Four Channels  transmitter & Receiver -  This is a very simple Wireless RF transmitter circuit that consists of the Holtek HT-12E encoder chip and AM 418MHZ-transmitter module (WZ-X01, other similar device can be used).  Using the hybrid RF xmit/receive modules make building the RF remote control a lot easy __ Contact info @ wzmicro.com

RF Modem RobotICs Project -  RF is just way too cool not to use in your designs.  But if you're a newbie like me it is difficult to successfully build solid RF transmitters and receivers.  When I started out I didn't realize that the larger breadboard I was working off of was causing a lot of the signal deviance because the metal traces on the breadboard worked like small capacitors and changed my circuit Dynamics.  So after much research I found the Reynolds Electronics RWS and TWS 434 RX/TX pair __ Designed by Rob Arnold

RF Power Detector with Buffered Output & >40dB Dynamic Range -  LTC5505-1 /LTC5505-2__ Linear Technology/Analog Devices

RF Power Meter -  RF Power Meter for QRPers __ Designed by Peter Parker VK3YE

RF Power Meter for QRPers -  Circuit only__ 

RF Power Meter for the QRPer -  amateur radio construction projects.   __ Designed by Peter Parker

RF Remote Control System -  With a handful of inexpensive components, a little creativity, and the power of PicBasic, you can build some pretty outstanding robotics creations as Rob Arnold proves with his Ruf-Bot project.   __ Designed by Rob Arnold

RF Signal Detector at 2.45GHz -  Many cordless telephones, computer networks and cell phones use a RF transmitter lefted on the 2.45GHz band.  Using a microwave diode detector and 100uA meter, this passive circuit will display the strength this signal.  The drawing shows how a bent piece of wire can be used as the antenna. . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

RF signal generator -  TR1 is a high gain FET (Field Effect Transistor) and is configured as a Colpitts style oscillator.  The oscillation frequency is set by the variable capacitor (C1+C2) and the five pairs of switched inductors.  There is significant overlap between the ranges, due to the limited range of readily available inductors.  However even by using specially would inductors, four frequency bands would have been needed to cover the range. __ Designed by Paul Stenning

RF sniffer finds 2.4-GHz sources -  11/23/06  EDN Design Ideas:  Locate interference sources in the iSM band Design by Vladimir Dvorkin, Linear Technology Corp, Milpitas, CA

RF Synthesizer Uses Generic ICs -  06/24/10  EDN Design Ideas:  You can design a hardware-based frequency synthesizer with one inexpensive IC and a few passive components.  Such synthesizer chips are not always available, however, because they are typically single-sourced and are not in stock w Design by James B Wood, Inovonics Inc, Felton, CA

RF Transmitter -  This is probably the simplest radio transmitter that you will find anywhere.  it has a total of five parts and can be constructed into a very samll space __ Designed by Andy Wilson

RF transmitter uses AM I encoding -  11/24/99 EDN Design Ideas:  Although alternate-mark-inversion (AMi]encoding is well-suited for direct-conversion FM transmission, designers often overlook the technique.  AMi, a three-phase, synchronous-encoding technique, uses bipolar pulses to represent logic ones and no signal to Design by Paul Sofianos

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