Flexiva™

The Flexiva Advantage

Maximum Efficiency
Flexiva is the most efficient solid-state FM transmitter available. Leveraging the Harris PowerSmart architecture, 50-volt LDMOS device technology delivers a dramatic increase in power density, lower operating costs and reduced cost of ownership over the life of the transmitter.

Compact Footprint and Lightweight Design
Flexiva is the most compact FM transmitter on the market, with a significantly reduced size compared with other products in its power class. Ideally suited to fit in crowded, shared transmitter sites, Flexiva reduces the cost and space required in the facility, simplifies installation, lowers shipping costs and allows for easier maintenance.

Highest Power – Elegant Simplicity
Flexiva achieves market-leading power levels (up to 20 kW). Featuring distributed control architecture, Flexiva delivers outstanding reliability, and enables soft failure operation and simple serviceability.

Low to High Power, Analog or Digital
From very low power (5 W) to very high power (20 kW and beyond), the Flexiva family does it all. Whether it is 50 W of analog FM or 20 kW of
FM+HD that is needed, Flexiva transmitters all provide the same outstanding value.

Improved Up Time
Hot-pluggable, redundant power amplifier (PA) and universal power supply (PS) modules make on-air servicing a breeze and eliminate costly service interruptions.

Reduced Service Costs
Lightweight and universal PA modules (broadband from 88 to 108 MHz; 4.5 kg) and PS modules (auto-ranging 90 to 264 VAC, 47 to 63 Hz; 2.5 kg) facilitate overnight/same-day shipment from a centralized depot for simplified and cost-effective spares holding. The use of lightweight modules virtually eliminates two-person lift requirements for routine maintenance. Flexiva also supports the simple replacement of pre-tuned amplifier pallets in the field, eliminating the need for complex tuning after FET replacement.

Smooth Upgradeability
Flexiva features world-class software-defined exciter technology, allowing for a seamless transition from analog to digital in the user’s time frame.

Advanced Digital Precorrection
Harris Real-Time Adaptive Correction (RTAC™) is an advanced type of digital precorrection that enables the exciter to more fully utilize the transmitter power amplifier, yet maintain spectral mask compliance of the digital signal.

Reliable, Distributed System Control
The Flexiva transmitter uses a central interface to a distributed control system. Featuring extensive protection and control capabilities, the main system control is located in the Flexiva amplifier bay and communicates with the exciter for mode switching. The distributed nature of the design provides for fast-acting independent protection at the module level for maximum reliability. A liquid-crystal control screen allows easy review of all operational parameters and easy diagnosis of any potential equipment problems. Front-panel buttons and bright LED indicators allow for simple control and feedback on all the key operating parameters. The navigation buttons allow for quick review, setup and recall of all menus via the front-panel screen. By simply connecting a PC to either the front- or rear-panel RF-45 jack, the user can monitor and control all the settings on the PC.

Advanced Global Monitoring and Control
In addition to local control, the Flexiva transmitter can be controlled from anywhere in the world with an intuitive, browser-based graphical user interface (GUI) over TCP/IP via a telecom or network connection with password protection.

Full Simple Network Management Protocol (SNMP) facilities are provided for network management of the entire transmission system using industry-standard MIB protocols.

Remote Communication
The following remote interfaces are available:
• GUI
• Ethernet network connection RJ-45 (10/100Base-T) with TCP/IP protocol
• Automated remote alarms in the event of a fault, which are sent via SNMP or e-mail with the connection to a network
• Simple, parallel interface to panels and remote control systems

Multi-System Controller (MSC)
To support greater redundancy, the Multi-System Controller (MSC) supports a range of backup options, including 1+1, full N+1 and dual-transmitter installations. The MSC monitors and controls the transmitter systems and controls RF switching.
 
Common Parts
The complete Flexiva line utilizes the same major parts — from the highest-power, air-cooled transmitter to the compact, low-power systems.

Advanced Digital Pre-Correction
There are two types of precorrection used: linear and nonlinear. Linear precorrection is for the non-ideal amplitude response and time response of the transmission system, including the power amplifier and any bandpass filters. Linear precorrection is helpful in optimizing the modulation performance of the transmitted digital signal so that less equalization is required at the receiver. Nonlinear precorrection is for the two major types of nonlinearity (AM->AM and AM->PM) in the RF power amplifier, which cause undesired spectral components and poor RF mask compliance.

AM to AM nonlinearity causes the RF power amplifier’s output amplitude to not accurately track the input amplitude. Typically, this nonlinearity occurs near the peak output power of the amplifier, where saturation effects cause the output response to flatten as the input continues to increase and where the amplifier output goes to zero. AM to PM nonlinearity causes the RF power amplifier’s output phase to not track the input phase. The amplifier acts like a phase modulator as the power output varies to follow the input signal, producing undesirable sidebands.

Precorrection can be implemented in many ways. In order of sophistication, they are:
• Analog fixed precorrection
• Digital fixed precorrection
• Digital adaptive precorrection
• Digital, memoryful, adaptive precorrection (RTAC)

Fixed precorrection can improve the system linearity for one specific operating point, but must be manually readjusted for changes in power output, antenna load impedance, temperature or operating point. Adaptive digital precorrection utilizes an RF sample taken at the output of the RF amplifier to automatically adjust the shape of the precorrection to continuously optimize the linearization of the system. The bandwidth limitation, especially in tube-type amplifiers (e.g., IOT), along with the stored energy in tuned circuits, introduces “memory effects.”

Digital, adaptive, memoryful precorrection can correct for these “memory effects” in addition to simple AM to AM and AM to PM distortions. Even wideband, solid-state RF amplifiers have some memory effects that make the shape of the nonlinearities change with the digital modulation data states. As the only system with simultaneous linear and nonlinear, adaptive and memoryful precorrection, RTAC provides the highest level of correction to all types of RF amplifiers.