Which diode is used as current controlled attenuator?

variable PIN Diode
The attenuator is a current controlled variable PIN Diode attenuator in the balanced Pi network configuration.

What characteristic of a PIN diode makes it useful as an RF switch?

Under zero or reverse bias, a PIN diode has a low capacitance. The low capacitance will not pass much of an RF signal. Under a forward bias of 1 mA, a typical PIN diode will have an RF resistance of about 1 ohm, making it a good RF conductor. Consequently, the PIN diode makes a good RF switch.

What Is PIN attenuator?

PIN diode-based Automatic Gain Control (AGC) attenuators are commonly used in many broadband system applications such as cable or fiberoptic TV, wireless CDMA, etc. The PIN diode is used as a current-controlled resistance component in the PI network.

How does a PIN diode work?

PIN diode basics A PIN diode behaves as a current-controlled resistor at radio and microwave frequencies. Like the conventional PN diode, it allows current flow in one direction when forward biased, but not in the other when it is reverse biased.

How can a PIN diode be used as an attenuator?

High quality RF switch and attenuator can also be made by PIN diode. In PI prototype network, PIN diodes are used as resistances which are controlled by current. We can design a attenuator which attenuation can be continuously tunable by three PIN diodes which replace R1 and R2 in Fig.

How does an RF attenuator work?

RF attenuators reduce the strength of an RF signal. RF attenuators are essentially electrical resistors that are put in line with an RF signal and reduce the signal strength by converting some amount of RF energy into heat. The amount of resistance used is what determines the amount of attenuation.

How does an RF switch work?

A Radio Frequency (RF) switch is a device that routes high-frequency signals through transmission paths. They also support the integration of multiple radios that use a single antenna. The need for RF switch circuits is due to the increasing demand for wireless communications at higher frequencies and wider bandwidths.

What is RF PIN diode?

A: The PIN diode is a special diode which can be configured as an RF switch. It has a wide, undoped intrinsic semiconductor region (“I”) sandwiched between a p-type semiconductor (“P”) and an n-type semiconductor region (“N”), hence the PIN designation. This is unlike a standard diode which has no intrinsic region.

What is a PIN diode limiter?

The PIN limiter diode can be described as an incident power- controlled, variable resistor. The presence of a large input signal temporarily forces the impedance of the diode to a much lower value, producing an impedance mismatch which reflects the majority of the input signal power back towards its source.

What is voltage controlled attenuator?

A voltage variable attenuator is an electronic device that provides a variable attenuation depending on the voltage applied. Unlike fixed attenuators whose attenuation cannot be adjusted by a user, the attenuation levels of variable attenuators can be changed to desired values.

What is attenuation RF?

Attenuation is a reduction of signal strength during transmission, such as when sending data collected through automated monitoring. 4 radio will likely encounter bit errors when decoding the signal. This problem worsens when significant RF interference is present.

How do you solve attenuation?

The most common way of dealing with this problem is to use repeaters(a device used to regenerate or replicate a signal)and hubs that will boost the signal strength ad hence prevent attenuation of the signals. This will also increase the maximum range that the signal can travel.