Introduction

When selecting an RF amplifier for your system, the decision between manual and auto-switching models can significantly impact system performance, efficiency, and flexibility. Though the distinction might seem subtle initially, understanding the operational differences and limitations of each type is crucial for ensuring optimal performance.

 

The choice of radio system selected for the application plays a vital role in determining if you can integrate a manual switching or auto-switching amplifier with the radio. The availability of specific options on the radio will determine what type of amplifier is best suited for pairing with a specific radio.

 

Read on to learn more about the differences between these two types of RF amplifiers and when they should be considered for integration.

 

Manual Switching Amplifiers

 

Manual switching amplifiers receive direct signals from the radio to toggle between transmit and receive modes. Typically, radios designed explicitly for integration with external amplifiers provide a dedicated control line for this purpose. This manual control offers several distinct advantages:

 

1. Immediate Switching Response: Because manual amplifiers are controlled directly by the radio, they switch rapidly, typically within a few microseconds. This precise synchronization ensures the amplifier is fully active and ready before the radio starts transmitting, avoiding any potential loss of critical data packets at the beginning of a transmission burst.
2. Greater Operational Flexibility: Manual amplifiers are not limited by input power thresholds for switching activation. They amplify signals effectively across a broader range of input power levels, providing superior flexibility in diverse operational scenarios. This means manual switching amplifiers are ideal for systems requiring variable output levels or operating in environments with fluctuating power requirements.

 

Auto-Switching Amplifiers

Auto-switching amplifiers, in contrast, automatically detect the presence of an RF signal to determine when to switch between transmit and receive modes. While convenient, this auto-detection mechanism introduces specific operational constraints:

 

1. Limited Power Range: Auto-switching amplifiers depend on internal detectors calibrated to function within defined power input ranges. Typically, these amplifiers operate optimally within about a 10 dB window of input power (for example, between 5 and 15 dBm). Operating outside this power range can lead to incomplete signal detection, causing the amplifier to either fail to activate or operate inconsistently.
2. Reduced Flexibility: Due to the input power range limitation described above, the main disadvantage of an auto-switching amplifier is a reduction of the usable output power range. There is a hard lower limit on the minimum output power that you can operate at with an auto-switching amplifier.

 

For instance, an auto-switching amplifier capable of 30 watts of peak power output will only be able to function correctly down to approximately 3.8 watts before its input detection circuitry begins to hit the limit of reliable detection. Although this seems to be a disadvantage, operating a 30W amplifier at that low an output power isn't efficient in real-world use scenarios.

 

10 dB of output power capability below the peak capability of a given output has seemed to be sufficient in practice. For example, if an application needed less than 3-4 watts out of the amplifier to begin with, it would be more prudent to select an amplifier with a lower peak power output.

 

Making the Right Choice

Select a manual switching amplifier when your radio has a dedicated transmit/ receive control line, or when your system requires precise, consistent synchronization and operational flexibility across a wide range of power levels. This scenario is common in professional and mission-critical applications, including military, surveillance, and high-performance communication systems.

 

Triad RF has spent over a decade integrating platform-agnostic amplifiers with many of today's leading MIMO/MANET radio systems. Below is a list of radio manufacturers with dedicated transmit/receive control lines compatible with our manually-switched BDAs:

 

• Domo Tactical Communications
• Silvus Technologies

 

Select an auto-switching amplifier if your radio does not support a dedicated control line for amplifier switching or if your application consistently operates within the amplifier's specified power range. Despite their limitations, autoswitching amplifiers are robust and straightforward for applications that do not demand extensive flexibility.

 

Below is a list of MIMO/MANET radio manufacturers that currently do not provide a control line to switch a BDA. Therefore, an integration with a Triad RF BDA would need to have the auto-switching option selected:

 

• Doodle Labs
• Persistent Systems
• Rajant
• XetaWave
• CreoMagic
• Microhard
• Mobilicom

 

For all other radio systems not listed, the best way to know is to ask the manufacturer if their radio systems have a dedicated control line with either a TTL or LVTTL output. If it does, Triad's BDA products with manual switching are compatible, as nearly every BDA that Triad manufactures offers this configuration.