UT320 and UT340
Ultrasonic Pulser Receiver Systems

Description
The UT340 Option - 002 filter module provides continuously variable second order low-pass and high-pass filtering as well as selectable RF signal inversion. It can be specified as an option for new UT340 pulser receivers or it can be retrofitted into existing UT340 instruments. The module works equally well with UT320 instruments.

Continuously variable filters offer many benefits that switchable filters cannot provide. The most important benefit is the precise positioning of the filter. The problem of being too far away or too close to the transducer center frequency is eliminated. The filters can slide from both sides in 1MHz steps.

The low-pass filter is primarily used for broadband noise reduction where the full 150MHz bandwidth of the UT340 is not required. Its very broad range (20-150MHz), makes it useful as a precision attenuator for downshifting/attenuation studies.

The high-pass filter is useful for increasing spatial resolution when using broadband ultrasonic transducers. It can also dramatically decrease amplifier recovery time, allowing ultrasonic work much closer to the main-bang pulse.

The invert function is useful for realigning maximum RF cycles for peak detection or for comparison after interface inversions.

Low-Pass

• noise reduction
• can be used as a frequency-based attenuator

High-Pass

• increased spatial resolution
• decreased amplifier recovery time
• allows work closer to main-bang pulse
• provides broadband transducer frequency up-shifting capability

Bandpass

• place filter skirts around transducer center frequency to reduce unwanted signals
• match frequency response of UT3xx to the passband of other instruments
• provides ultra-flat and ripple-free response in the passband region

Computer Control

• all filter and invert functions can be controlled by a remote computer
• settings can be saved and recalled from the instrument front panel
• settings can be saved and recalled from the remote computer

Specifications