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• 10MHz TO 20MHz LASER LIGHT DETECTOR
  This circuit was originally designed to detect laser light pulses for an optical Ethernet communications system. It has good ambient light immunity.

• 20MHz VCSEL 3mW LASER TEST CIRCUIT
  This circuit takes advantage of some new vertical cavity surface emitting lasers (VCSEL) that don’t require light output control circuits. The circuit shows how to drive the device from a single high speed CMOS IC. The circuit can easily be modified to transmit signals from kilohertz to about 50MHz.

• BROAD BAND 5MHz OPTICAL FIBER RECEIVER
  This circuit is a simple broad band light detector that uses a very inexpensive IC and a PIN photodiode that is packaged for use with plastic optical fibers. It has a bandwidth from 1KHz to over 5MHz.  It is great for experimenting with various modulated light sources.

• BROAD BAND 2MHz OPTICAL FIBER RECEIVER
  If you need more sensitivity than the above circuit this circuit provides about ten times more gain. It too is designed around an inexpensive plastic optical fiber detector.

• CMOS Logic Inverter Amplifier Characteristics
  This chart shows some of the measured characteristics of three different unbuffered CMOS logic gates, used as voltage amplifiers.

• C-MOS INVERTER MAKES LOW POWER AMP
  With the addition of one resistor and a capacitor, some common logic ICs can be transformed from digital to analog duties.  This circuit outlines some the features to expect from different inverter ICs.

• FET INPUT HIGH SPEED LIGHT DETECTOR
  This circuit is yet another design that converts current from a PIN photo diode to a voltage.   It has a bandwidth that extends beyond 50MHz.

• N-CH AND P-CH TRANSISTORS FORM PUSH-PULL DRIVER
  This circuit can produce high speed output signals with fast rise and full times. The unique change pump action allows the voltage of the upper P-ch device to range from millivolts to hundreds of volts. The output current is only limited by the rating of the transistors. I have used this circuit beyond 2MHz.

• WIDE BAND ZERO CROSS DETECTOR
  This circuit was designed to convert a low amplitude 40KHz signal into a clean square wave signal.  It will work with inputs as small as 5mv peak-to-peak or as large as 3 volts peak to peak.  The input frequency can range from a few kilohertz to about 150KHz.

10W HF Linear Amplifier:  (Circuit / schematic design added 6/06)

27MHz toy car receiver:  (Circuit / schematic design added 6/06)

3W HF QRP Linear Amplifier:  (Circuit / schematic design added 6/06)

5 Watt HF CW Transmitter:  (Circuit / schematic design added 6/06)

500mW HF Linear Amplifier:  (Circuit / schematic design added 6/06)

500w HF Linear Amplifier:  (Circuit / schematic design added 6/06)

Active Antenna for Am-Fm-Sw:  (Circuit / schematic design added 6/06)

Active Antenna for HF-VHF-UHF:  (Circuit / schematic design added 6/06)

Build an Adjustable High Frequency Notch Filter:  02/06/03 EDN Design Ideas  /  (added 12/04)  Although you can obtain universal, resistor-programmable switched-capacitor filters that are configurable as notch filters, most cannot operate at bandwidths higher than 100 kHz. Further, the typically 16- to 20-pin packages do not include a continuous-time, antialiasing filter to prevent spurious signals from appearing at the output....

Composite Amp Provides High Gain and Bandwidth:  04/28/94 EDN-Design Ideas / (Electronic Schematic / circuit added 04/02) The composite circuit in Fig 1 couples the output drive and slew rate of a current-feedback amplifier, IC2, with the low-noise and low-offset characteristics of a voltage-feedback operational amplifier, IC1. The circuit achieves gains as high as 1000, while showing little variation in frequency characteristics with gain. This circuit suits applications requiring high gain and wide dynamic range, such as ultrasound, radar, digital radio, and other high-noise applications....    

LF to HF Converter:  (added 2/05)

Low-cost bias circuits serve HF and VHF bands:  09/14/00 EDN-Design Ideas / (Circuit / schematic design added 6/06)  

QRP HF Transmitter:  (Electronic Circuit added 03/06)

Singlesideband Demodulator Covers the HF Band:  10/26/00 EDN-Design Ideas / (Circuit added 9/04)

Synthesized HF Receiver:  (Circuit / schematic design added 6/06)

TBA120 Narrowband FM Receiver:  (Circuit / schematic design added 6/06)

Wideband AGC has 60 DB Dynamic Input Range:  10/10/96 EDN-Design Ideas / (Electronic circuit added 5/02)   

Wideband Filter uses Image Parameters:  10/26/00 EDN-Design Ideas / (added 05/03)

Wideband Low Noise Amplifier Drives 50 Ohm Loads:  10/23/97 EDN-Design Ideas / (Electronic Schematic / circuit added 4/02)  

Wideband Opamp Capable of Micropower Operation :  National Semiconductor Application Note 24-Oct-2001 (added 1/03)