Cat5e Shielded | RF Amplifiers | Cellular Repeate | Wireless Products

Coax Cable is a type of wire that consists of a center wire surrounded by insulating materials and then a grounded shield of braided wire. Coax cable is a cable type used to carry radio signals, video signals, measurement signals and data signals. The shield minimizes electrical and radio frequency interference.

Coax cabling is the primary type of cabling used by the cable television industry and is also widely used for computer networks, such as Ethernet. It is more expensive than standard telephone wire; it is much less susceptible to interference and can carry much more data than a telephone wire.

A coax cable consists of two conductors that share a common axis. The inner conductor is typically a straight wire, either solid or stranded and the outer conductor is typically a shield that might be braided or a foil. Coax cables exist because we can't run open-wire line near metallic objects (such as ducting) or bury it. We trade signal loss for convenience and flexibility.

Coax cable consists of an insulated center conductor which is covered with a shield. The signal is carried between the cable shield and the center conductor. This arrangement give quite good shielding agains noise from outside cable, keeps the signal well inside the cable and keeps cable characteristics stable.

The cable is designed to carry a high-frequency or broadband signal, as a high-frequency transmission line. Sometimes DC power (called bias) is added to the signal to supply the equipment at the other end, as in direct broadcast satellite receivers. Because the electromagnetic field carrying the signal exists (ideally) only in the space between the inner and outer conductors, it cannot interfere with or suffer interference from external electromagnetic fields.

Coax cables may be rigid or flexible. Rigid types have a solid sheath, while flexible types have a braided sheath, both usually of thin copper wire. The inner insulator, also called the dielectric, has a significant effect on the cable's properties, such as its characteristic impedance and its attenuation. The dielectric may be solid or perforated with air spaces. Connections to the ends of coax cables are usually made with RF converter.

Shireen Inc. has rolled out an optical repeater module designed for WCDMA networks. The RF module is used to monitor and control optical output power, LD bias current, received optical power, input and output RF signal power of Master, received FSK signal power and RF Gain control through the MCU. It is also used for RoHS compliant products.

The optical module for the repeater includes a linear analog PD with high sensitivity and a high power DFB laser, a low noise, linear RF amplifiers, as well as built-in Bi-Di components and FSK monitor. 9.6 and 19.2kbit/s data rates are provided for selection. In the slave, a laser with a wavelength of 1.5µm is selected as transmitter and an analog PD as optical signal receiver.

About Shireen Inc.

Shireen, Inc. designs, develops and manufactures components and systems for the Broadband Wireless, SCADA, Military and Telecommunications industries. Our solutions include everything from “mission critical” components for military communication systems to increasing the power of WiFi installations.

The optical module for the repeater includes a linear analog PD with high sensitivity and a high power DFB laser, a low noise, linear RF amplifier, as well as built-in Bi-Di components and FSK monitor. 9.6 and 19.2kbit/s data rates are provided for selection. In the slave, a laser with a wavelength of 1.5µm is selected as transmitter and an analog PD as optical signal receiver.

The optical module for the repeater includes a linear analog PD with high sensitivity and a high power DFB laser, a low noise, linear RF amplifier, as well as built-in Bi-Di components and FSK monitor. 9.6 and 19.2kbit/s data rates are provided for selection. In the slave, a laser with a wavelength of 1.5µm is selected as transmitter and an analog PD as optical signal receiver.

Efficiency and make of a RF amplifier determines the class it belongs to. Class E amplifiers are considered to be the best as they deliver significantly higher quality signals as compared to other class amplifiers. Transistor in Class E amplifiers works as a switch with a similar on/off function. Load network mechanism molds the current voltage and waveforms in a manner so as to avoid high voltage and current occurrences to limit power spread especially when the transistor switches on and off.

When the same transistor at the same frequency and output power is run in Class E, B and C amplifiers, Class E amplifier will operate more efficiently with power loss of less than 2.3 as compared to Class B and C amplifiers. They can be designed to handle frequency operations as large as 225-400 MHz during a fixed tune or narrow band operation. Class B and E amplifiers have same level of harmonic output. One big advantage of Class E amplifier is that they are “designable”, you can say customizable to make it simpler to understand. If you define the frequency variations and component effects in advance when designing Class E amplifiers then they will perform as expected.

To increase the efficiency of RF amplifiers it is important to reduce the power dissipation and still get the preset power output. Consider a RF amplifier and the greatest power dissipation in the entire system happens in the power transistor. Though the transistor has to be designed so as to be able to resist high power voltage and current, its power dissipation can be reduced by ensuring that both high voltage and current do not occur at the same point of time. If this can be attained through changes in the design then the efficiency of RF amplifiers can be increased substantially.

When “On” and the current is really high the transistor switch will work as a low resistance closed switch and the voltage will become zero. When “Off” and the voltage is high the transistor switch will work as an open switch and the current will become zero.

Similarly there are many different alternatives to increase the efficiency of Class E RF amplifier.