Herotek LL2018-1 vs LL2018-2 vs LL2018-3 2–18GHz RF Limiters
The Herotek LL2018-1, LL2018-2 and LL2018-3 are 2–18GHz very-low-leakage RF limiters designed to protect sensitive LNAs and microwave receiver front ends.
The three models share the same frequency range, insertion loss, VSWR and power-handling ratings. Their main differences are the typical leakage range and limiting threshold. The LL2018-1 provides the lowest leakage and earliest limiting action, while the LL2018-3 allows a higher output level before compression.
LL2018-1, LL2018-2 and LL2018-3 Comparison
| Parameter | LL2018-1 | LL2018-2 | LL2018-3 |
| Manufacturer | Herotek | Herotek | Herotek |
| Product Type | Very-Low-Leakage RF Limiter | Very-Low-Leakage RF Limiter | Very-Low-Leakage RF Limiter |
| Frequency Range | 2–18GHz | 2–18GHz | 2–18GHz |
| Maximum Insertion Loss | 4dB | 4dB | 4dB |
| Maximum VSWR | 2.0:1 | 2.0:1 | 2.0:1 |
| Typical Leakage Level | −10 to −5dBm | −5 to 0dBm | 0 to +5dBm |
| Typical Limiting Threshold | −10dBm | −5dBm | 0dBm |
| Maximum CW Input Power | 1W | 1W | 1W |
| Peak Input Power | 100W | 100W | 100W |
| DC Supply | +5V, 5mA typical | +5V, 5mA typical | +5V, 5mA typical |
| Package Style | 1D | 1D | 1D |
| Operating Temperature | −55°C to +125°C | −55°C to +125°C | −55°C to +125°C |
Herotek LL2018-1: Lowest Leakage Level
The LL2018-1 provides a typical leakage range of −10 to −5dBm and a typical limiting threshold of −10dBm.
It is the most protective option in the LL2018 family and is suitable for receiver front ends containing sensitive LNAs, mixers or other components with low allowable input-power levels.
Choose the LL2018-1 when:
The protected device has a low damage threshold
Minimum output leakage is the primary requirement
Limiting should begin at a relatively low input level
Receiver sensitivity is more important than allowing higher signal levels
Herotek LL2018-2: Balanced Protection
The LL2018-2 provides a typical leakage range of −5 to 0dBm and a typical limiting threshold of −5dBm.
It offers a middle option between the stronger limiting action of the LL2018-1 and the higher threshold of the LL2018-3.
Choose the LL2018-2 when:
The receiver requires low leakage without the lowest available threshold
Moderate signal levels should pass before limiting begins
A balanced solution is required for broadband 2–18GHz protection
The LL2018-1 would clamp the signal too early
Herotek LL2018-3: Higher Limiting Threshold
The LL2018-3 provides a typical leakage range of 0 to +5dBm and a typical limiting threshold of 0dBm.
It is intended for receiver systems that can tolerate a higher residual output level and need to preserve stronger wanted signals before the limiter enters compression.
Choose the LL2018-3 when:
The protected component can tolerate higher input power
A 0dBm limiting threshold is acceptable
Premature limiting must be avoided
Higher signal levels need to pass through the receiver path
Features and Applications
The LL2018 series uses a hermetically sealed module with removable connectors for circuit-board integration. Typical applications include receiver protection and RF power leveling. The devices require a +5V supply with approximately 5mA typical current consumption.
Common applications include:
Broadband LNA protection
Radar receiver front ends
Electronic warfare receivers
Microwave test equipment
Signal intelligence systems
RF power-level limiting
Communication receiver protection
Before selecting a model, confirm the maximum incident power, pulse width, duty cycle, LNA damage threshold, acceptable insertion loss and permitted leakage level.
Ordering Information
DataStorageIC supports international inquiries for Herotek low-leakage RF limiters, including:
LL2018-1, LL2018-2 and LL2018-3 quotations
Current price and lead-time confirmation
Datasheet and technical support
Leakage-level and threshold selection
Alternative Herotek limiter models
International RFQ and delivery support
Please provide the required model, quantity, receiver frequency, maximum input power, protected-device threshold and destination country when requesting a quotation.
Frequently Asked Questions
What is the main difference between LL2018-1, LL2018-2 and LL2018-3?
The models have different leakage and limiting-threshold levels. The LL2018-1 has the lowest leakage, while the LL2018-3 has the highest threshold.
Which model provides the strongest LNA protection?
The LL2018-1 provides the lowest typical leakage range of −10 to −5dBm and is the most suitable starting point for highly sensitive LNAs.
Do the three models have different frequency ranges?
No. All three models operate from 2GHz to 18GHz.
Do LL2018 limiters require a power supply?
Yes. The LL2018 series requires a +5V DC supply with approximately 5mA typical current consumption.
What input power can the LL2018 series handle?
Herotek specifies a maximum input power of 1W CW and 100W peak for microsecond-duration pulses.
How should the correct leakage level be selected?
The limiter’s maximum leakage should remain below the safe input-power level of the protected LNA, mixer or receiver component.
