Toolbar   The Engineering Toolbar
The Ultimate Resource for Engineering and Technical Research. (Learn More)

Is Bias Current Necessary? - App Note

From Avago Technologies
 

 
Conventional Schottky detector diodes are tested and specified with 20 microamperes of DC bias. The bias current reduces the junction resistance so that most of the detected voltage appears across the load resistance. In some applications the diode is used to monitor power rather than to detect a low level signal. In this case, the signal level may be high enough to reduce the junction resistance sufficiently without the use of DC bias. A detector diode may be considered as a voltage source in series with the diode resistance. The output voltage is taken from a load resistance in series with the diode. This circuit is a voltage divider. The detected voltage is divided between the diode and the load. The useful output voltage is. For best performance the ratio of diode resistance to load resistance should be small. In many cases load resistance cannot exceed 100 K ohms in order to keep the response time small enough to handle fast pulses.
Products & Services
PIN diodes are three-layer semiconductor diodes consisting of an intrinsic layer separating heavily doped P and N layers. The charge stored in the intrinsic layer in conjunction with other diode parameters determines the resistance of the diode at RF and microwave frequencies. Search by Specification | Learn more about PIN Diodes
Schottky diodes in their simplest form consist of a metal layer that contacts a semiconductor element. The metal / semiconductor junctions exhibit rectifying behavior (i.e., the current passes through the structure more readily with one polarity than the other). Search by Specification | Learn more about Schottky Diodes
Diode arrays are composed of multiple discrete (usually unconnected) diodes on a single silicon chip. Diode arrays are important semiconductor products because they save assembly time and improve reliability over individually packaged diodes. In general, diode arrays use four or more diodes in a single package. Search by Specification | Learn more about Diode Arrays
RF diodes are designed to handle high-power radio frequency (RF) signals in stereo amplifiers, radio transmitters, television monitors, and other RF or microwave devices. Search by Specification | Learn more about RF Diodes
Power diodes are used mainly in high-power applications. They are built with large P-N junctions in order to pass large amounts of current and dissipate large amounts of heat. Search by Specification | Learn more about Power Diodes
Product Announcements
UltraVolt, Inc. - "HVA" Series High Voltage Amplifiers
The "HVA" Series of DC-to-DC HV power supplies operates a precision filter/divider & linear HV switch to produce a High Voltage Amplifier (HVA). These new modules provide a high-resolution,... (read more)
American Microsemiconductor, Inc. - Diodes, All Types of diodes, We Have Your Diode
In this discussion the term diode and rectifier will be used interchangeably, a low current rectifier implies a diode,and a high current or power device, conducting from 1 to 1000 amps or even higher,... (read more)
Sage Laboratories - Frequency Activity Detector
Activity Detector Unit - Many advanced EW receivers, particularly those associated with ECM jamming systems do not require the high resolution frequency information associated with a DFD or IFM based... (read more)
UltraVolt, Inc. - XS Series Extra-Small Microsize HV Power Supply
The "XS" Series extra-small high-voltage power supplies at only 0.08in3 [1.3cc] is the smallest regulated DC-DC high-voltage power supply for bias supplies, APDs and MPPCs that need a bias voltage... (read more)
American Microsemiconductor, Inc. - COMMON DIODE APPS: Steering & free-wheeling by AMS
Diodes are frequently referred to by their function in a circuit rather than their parameters or part number. Two examples are parts ordered as free- wheeling or as steering. These terms do not... (read more)
American Microsemiconductor, Inc. - Tunnel Diode and Back Diode by AMS
American Microsemiconductor supplies tunnel diodes. Tunnel diodes have a negative resistance region that allows for very fast switching speeds, up to 5 GHz. (read more)
iC-Haus GmbH - 15 V P-Type CW Laser Diode Driver
iC-WKP is a driver for laser diodes in continuous wave operation with laser currents of up to 350 mA which requires only four external components. The Driver is optimised for use with P-type laser... (read more)
Photonic Products Ltd. - Opnext HL6385DG 642nm 150mW Laser Diode
Photonic Products is the authorised distributor of the World's first 642nm, 150mW, single longitudinal mode semiconductor laser diode with TE mode oscillation; the Opnext HL6385DG. (read more)
Topics of Interest
A conventional Schottky diode detector such as the Avago Technologies HSMS-8101 requires no bias for high level input power - above one milliwatt. However, at low levels, a small amount of dc bias is... (Read More)
The zero bias Schottky diode detector is ideal for RF/ID tag applications where it can be used to fabricate a receiver which consumes no primary power. However, its performance is heavily dependent... (Read More)
This application note has been written to demonstrate how the Avago Technologies EEsof ADS software package can be used to simulate a diode detector circuit reliably against temperature. For this... (Read More)
Zero bias detectors with higher forward voltage have better voltage sensitivity. For example, the HSCH-3206 with a forward voltage of about 200 millivolts at 0.1 milliampere is better than the... (Read More)
3.6 Bias Box Noise It is useful to estimate the detection noise and performance of the simple bias box system described in Chap. 2. We will assume that we are using a BPW34 silicon diode (a... (Read More)
See more product announcements for PIN Diodes
50MHz – 4GHz PIN Diode Variable Attenuator Module

50MHz – 4GHz PIN Diode Variable Attenuator Module
Avago Technologies


JAN-qualified diodes

JAN-qualified diodes
Aeroflex / Metelics


Si Dual Photo Diode

Si Dual Photo Diode
PREMA Semiconductor GmbH


11 See more product announcements for PIN Diodes