Teledyne Defence & Space (TDS) has over 30 years of experience in the design and manufacture of Detector Log Video Amplifiers (DLVAs). These devices are used extensively in applications requiring an output voltage related to the power of a received RF signal. These units are used primarily in direction finding, channelised receivers, and phase array radar.
In order to cope with a wide range of input signals, a log amplifier is used to provide a linear voltage output per dBm of input power. Continuous product development over many decades has resulted in further product refinements that now include the Teledyne Defence & Space Hybrid DLVA (LMV056 & LMV073) and SDLVA (Successive Detector Log Video Amplifiers) (RV075). Each version has advantages and disadvantages.
|Freq Range (GHz)||2-18||2-18||2-18||2-18||18-40|
|Dynamic Range (dBm)||-70 to +10||-60 to +7||-65 to +5||-60 to +5||-40 to +5|
|Freq Flatness (dB)||±2||±2||±2.5||±2.75||±3.5|
|Log Linearity (dB)||±1||±1.5||±2||±1.75||±1|
|Rise Time (ns)||15||30||15||15||25|
|RF Gain (dB)||N/A||N/A||N/A||>45||N/A|
|RF Saturation (dBm)||N/A||N/A||N/A||+12||N/A|
|Temp Range (OC)||-40 to +85||-40 to +85||0 to +85||-20 to +85||-10 to +85|
SOME STANDARD DLVAs / SDLVAs (Please email email@example.com with your specific needs)
TDS leverages its own DLVAs in the company’s sub-system designs, including the Compact 2-18GHz RWR (RR017). TDS offers over 38 different designs with thousands of units shipped to date, and is major supplier to large defence contractors.
The traditional DLVA is a single diode device, and so has a typical dynamic range of about 40dB. Recovery time is the time taken for a DLVA to go from a maximum output back down to being able to register a threshold-level signal. This takes a long time in a traditional DLVA because the detector circuit is saturated and the capacitors take a relatively long time to fully discharge.
Hybrid DLVAs and sequential DLVAs have multiple detector stages, each operating over a relatively small part of the full dynamic range. Consequently they can discharge faster at the end of a pulse, so the recovery time is shorter. Hybrid DLVAs usually have two or three detector stages, whereas SDLVAs have six or seven detector stages. This is why SDLVAs have the best pulse recovery performance, but Hybrids have better frequency flatness.
Some SDLVAs have a built-in limited RF output, which can be used to drive an IFM (eliminating the need for a separate RF path and limiting amplifier in the IFM).
TDS SDLVA/DLVA PRODUCTS AT-A-GLANCE