LINEARIZER TECHNOLOGY

Clearly Understanding Linearizers

A Linearizer is a module that is placed in front of an amplifier. The function performed by the linearizer in relation to the amplifier is very similar to how eyeglasses perform in relation to the eye. The eye distorts the image seen: eyeglasses pre-distort the image. When these two distortions are combined, the result is a clear image. For the nearsighted, the eyeglass must pre-distort the image one way. For the farsighted, the image must be pre-distorted in the opposite way. The lens of the glass must be shaped to match a particular sight distortion. In the same way, LTI engineers solutions to cancel distortion at any frequency and bandwidth.

Linearizers Empower the Information Age

Problem: When information is sent by radio or satellite, power must be increased to a level sufficient for successful transmission. The device that increases signal strength is an amplifier. In many radio frequency (RF) and microwave communications systems, the necessary strength can be quite high. Consequently, the required high power amplifier (HPA) is large and expensive. 

Solution: Highly linear amplifiers are essential for clear communications. Modern communication systems require their signals to be amplified with minimal distortion. Both cellular and analog radio transmissions need amplifiers with very high linearity, but most amplifiers are inherently non-linear. LTI linearizers boost output and cut distortion enabling critical communication systems to perform more efficiently and reliably with greater output.

Quadruple Output and Increased Efficiency by 50%

Matching linearizers to amplifiers is complex, because amplifiers operate at different frequencies and power levels, and are used for different applications. Linearizers must be finely tuned to cancel the distortion of a particular non-linear amplifier. When properly adjusted, a linearizer can virtually eliminate HPA distortion. This often allows an HPA to more than quadruple its effective output power while increasing its efficiency by more than 50%. Thus, LTI linearizers can significantly reduce the cost of HPA operation. Many systems would not be economically or even technically feasible without LTI linearization.

Tuning a Linearizer to Meet Your Needs

Our BLFE and BAFL Series linearizer products are usually supplied to manufacturers of TWTA, Klystron and “well behaved” SSPA type amplifiers. Our GLFE Series linearizers are suited for SSPA type amplifiers manufactured with GaN type devices. GaN devices can cause unstable characteristics and undesirable memory effects which can be challenging. Our MPM Series linearizers are specifically designed for manufacturers of Microwave Power Modules. The performance will be the same but the devices will be designed for the more compact form factor, and to meet lower voltage MPM requirements.

Aftermarket Solutions and Services

Most linearizers LTI produces are supplied to manufacturers of HPAs. However, linearizers are also supplied to amplifier users, typically to satellite ground stations and teleports, as aftermarket devices. These customers already have HPAs, but now need greater linearity. Our WAFL linearizer products are appropriate for this type of application. Knowledge of the characteristics, properties, and intended uses of the amplifier to be linearized is important. LTI linearizers can be adjusted in the field to match a specific amplifier. This process is not complicated and typically requires only a few minutes. However, the linearizer must be designed for the particular amplifier class. The process of producing a linearizer can vary greatly in time depending on the amplifier’s characteristics.

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