Non-Linear Junction Detector


User Manual


Ecological Certificate

Application Video

The non-linear junction detector (NLJD) LORNET-36 is designed to detect hidden electronic devices which contain semiconductors with p-n junctions such as covert audio and video transmitters, audio and video recorders (more generally referred to as eavesdropping devices), actuation and timer circuitry of improvised explosive devices (IED's). LORNET-36 features a constricted antenna directivity pattern which provides enhanced spatial selectivity and makes it an instrument of choice for conducting search operations in premises with high density of various electronic components.



  • LORNET-36 is the world's first NLJD which uses a high frequency probing signal of 3.6 GHz.
  • High frequency of the probing signal in combination with a parabolic transmit antenna allow for a very narrow beamforming (only 16 degress wide) which has opened entirely new capabilities in an NLJD: remote detection of tiny target objects and their spatial selection.
  • The 3.6 GHz probing mode provides unrivalled capabilities of detecting tiny semiconductor elements hidden by various materials (the detection occurs through small slots and apertures in the cover, ungrounded shielding as wells via smooth surface reflections).
  • The 3.6 GHz probing mode provides unrivalled capabilities of detecting tiny semiconductor elements hidden by various materials (the detection occurs through small slots and apertures in the cover, ungrounded shielding as wells via smooth surface reflections).
  • The negative electromagnetic impact upon the operator has been dramatically reduced thanks to a very low duty cycle of probing pulses and a very low rear lobe of the transmit antenna.
  • The convenient control interface familiar to users from other LORNET models makes operation easy and straightforward.
  • LORNET-36 has been built with innovative technology and materials resulting in exceptional performance, light weight and improved ergonomics.


An NLJD operation principle is based on illuminating a certain object under search with high power RF energy (either CW or pulsed) and on receiving the re-emitted object response at the multiples of the probing signal frequency (its second and third harmonics). The NLJD capability of detecting hidden electronics comes from the non-linear properties of semiconductors. Any electronic device will contain some printed circuit boards (PCB's) with conductors (virtual antennas) to which various semiconductor elements (diodes, transistors, microchips) are connected. For a high frequency probing signal all these elements can be considered as non-linear reflectors. This high frequency probing signal will induce in these conductors an alternating emf being converted by elements with a non-linear volt-ampere characteristic into RF signals on multiples (harmonics) of the probing frequency. These harmonics will be eventually re-emitted into space and detected by the NLJD's receivers tuned to these very frequencies. Detecting the 2-d and 3-rd harmonics of the probing signal by NLJD's receivers will mean that a hidden radioelectronic device is present in the illuminated area regardless of whether this device is powered on or switched off. It is conventionally assumed that the detected non-linear object is artificial in origin if the second harmonic's level exceeds that of the third one. If opposite is the case then the detected object is considered a natural non-linear junction of MOM-type (metal-oxide-metal). However, the NLJD application practice tells us that the mentioned criterion of the object origin identification may not always work well (e.g. a rusty metal element may exhibit a higher second harmonic level). In such a case additional identification methods may prove useful. This is where harmonics spectrum analysis will come really handy. In an ambiguous situation one may want to apply some physical impact on the object under search (e.g. knocking at it) while observing the second and third harmonics spectrum (or listening to the demodulated harmonics response in the headphones). The natural objects under a physical impact will show spectrum widening (regrowth) whereas the harmonics spectrum of artificial (electronic) object will remain largely unchanged. During demodulation the spectrum regrowth will manifest itself as a rustling noise in the headphones.


Probing Signal Frequency

3581.5 MHz, 3594.5 MHz, 3607.5 MHz

The probing frequency is selected automatically when the device is powered on based on the criterion of minimal interference in the 2-d harmonic receive path.
Transmit Antenna Gain 20 dB (relative to an isotropic antenna)
Transmit Antenna Directivity Width  16 degrees (at -3 dB level)
Probing Signal Maximum Power (Peak/Average)
Low Duty Cycle Pulse Mode 18 W/112 mW (duty cycle 0,625%)
High Duty Cycle Pulse Mode 12 W/600 mW (duty cycle 5%)
Probing Signal Power Adjustment Range 22 dB (11 steps)
Receiver frequencies correspond to the 2-d (2xF) and 3-rd (3xF) harmonics of the probing signal
Receivers sensitivity -110 dBm (measured in coaxial environment, without antennas, with a calibration signal applied from a test signal generator directly to the receiver input)
Receive Path Dynamic Range 30 dB
Operation Time from the built-in accumulator at the maximum rated power 3 hours in the low duty cycle pulse mode; 2 hours in the high duty cycle pulse mode
NLJD Dimensions, cm 47х32х19 (32х32х22 folded up)
NLJD Weight in the operating mode 1,4 kg
Carrying Bag Dimensions, cm 45х30х35
NLJD Weight in the carrying bag 3,6 kg
Operation Temperature Range +5...+40°С


LORNET-36 High Frequency NLJD US$ 7,900
The delivery set includes: NLJD LORNET-36, two replaceable LI-ION batteries, a 220V battery charger, a battery charging container, wireless headphones with receiver, a 220V receiver adapter, NLJD carrying bag and operation manual.