Nova Microwave High-Power Low-Loss Circulator Selection Guide | 150W–250W
Nova Microwave High-Power Low-Loss Circulator Selection Guide
High-power RF transmitters and power amplifiers require circulators that can handle significant forward and reflected power without adding excessive insertion loss.
Nova Microwave offers a dedicated range of High-Power, Low-Loss Drop-In Circulators designed for these applications. The current ETC and ETCE families cover approximately 1.7 GHz to 3.5 GHz, with selected models supporting up to 250 W forward power and insertion loss as low as 0.15 dB.
For the complete Nova Microwave product range, visit our Nova Microwave product page.
Why Low Insertion Loss Matters in High-Power RF Systems
Insertion loss may appear small when expressed in dB, but its effect becomes much more important as RF power increases.
For example, in a 250 W transmitter chain, reducing circulator insertion loss helps:
Reduce RF power dissipated as heat
Improve overall transmitter efficiency
Lower thermal stress around the PA output stage
Deliver more available RF power to the antenna or load
Nova Microwave's ETC0215 and ETC0240, for example, are specified with insertion loss as low as 0.15 dB, making them particularly attractive for high-power narrowband applications.
Nova Microwave ETC vs ETCE Series
Nova's high-power low-loss range can generally be divided into two useful groups.
ETC Series — Lower Loss for Narrower Frequency Bands
The ETC models typically target narrower operating bands and provide very low insertion loss.
Typical characteristics include:
Up to 250 W forward power
100 W reverse power on many models
22–23 dB minimum isolation
0.15–0.20 dB maximum insertion loss
Compact drop-in configuration
These models are well suited to RF systems where efficiency and low loss are more important than very wide bandwidth.
ETCE Series — Wider Frequency Coverage
ETCE models provide wider operating bandwidth while maintaining high power capability.
Typical characteristics include:
Up to 250 W forward power
100 W reverse power
21 dB minimum isolation
Approximately 0.21–0.23 dB insertion loss
Wider frequency range than many ETC models
The ETCE family is useful when one circulator needs to cover a broader operating band.
Nova Microwave High-Power Low-Loss Models
| Model | Frequency Range | Isolation Min. | Insertion Loss Max. | Forward Power | Reverse Power |
|---|---|---|---|---|---|
| ETC0175 | 1.710–1.800 GHz | 22 dB | 0.20 dB | 250 W | 100 W |
| ETC0185 | 1.805–1.885 GHz | 23 dB | 0.18 dB | 250 W | 100 W |
| ETC0196 | 1.930–1.990 GHz | 23 dB | 0.17 dB | 250 W | 100 W |
| ETC0215 | 2.100–2.200 GHz | 23 dB | 0.15 dB | 250 W | 100 W |
| ETC0240 | 2.300–2.500 GHz | 22 dB | 0.15 dB | 250 W | 100 W |
| ETC0260 | 2.500–2.700 GHz | 22 dB | 0.15 dB | 150 W | 110 W |
| ETCE0185 | 1.700–2.000 GHz | 21 dB | 0.23 dB | 250 W | 100 W |
| ETCE0205 | 1.920–2.170 GHz | 21 dB | 0.21 dB | 250 W | 100 W |
| ETCE0225 | 2.100–2.400 GHz | 21 dB | 0.21 dB | 250 W | 100 W |
| ETCE0255 | 2.400–2.700 GHz | 21 dB | 0.21 dB | 250 W | 100 W |
| ETCE0290 | 2.700–3.100 GHz | 21 dB | 0.21 dB | 250 W | 100 W |
| ETCE0330 | 3.100–3.500 GHz | 21 dB | 0.21 dB | 150 W | 110 W |
The final model should always be checked against the latest manufacturer specifications and the actual thermal, mechanical and RF conditions of the application.
How to Select the Right Model
1. Start with the Required Frequency Range
Frequency coverage is the first selection criterion.
For narrow operating bands, an ETC model may provide lower insertion loss.
For example:
1.71–1.80 GHz: ETC0175
1.805–1.885 GHz: ETC0185
1.93–1.99 GHz: ETC0196
2.10–2.20 GHz: ETC0215
2.30–2.50 GHz: ETC0240
2.50–2.70 GHz: ETC0260
If a wider bandwidth is required, consider ETCE models such as ETCE0185, ETCE0225 or ETCE0255.
2. Check Both Forward and Reverse Power
Forward power alone is not enough for circulator selection.
In an RF transmitter, impedance mismatch at the antenna or load can cause power to be reflected back toward the PA.
For this reason, check:
Normal operating forward power
Maximum peak power
Expected reflected power
Load VSWR
Protection requirements under mismatch conditions
Most of the ETC and ETCE models listed above support 100 W reverse power, while ETC0260 and ETCE0330 are rated at 110 W reverse power.
Adequate design margin is recommended rather than operating continuously at the specified maximum rating.
3. Compare Insertion Loss
For high-power designs, lower insertion loss usually means lower RF power dissipation.
The following models are especially attractive where efficiency is a priority:
| Model | Frequency | Insertion Loss |
|---|---|---|
| ETC0215 | 2.10–2.20 GHz | 0.15 dB max. |
| ETC0240 | 2.30–2.50 GHz | 0.15 dB max. |
| ETC0260 | 2.50–2.70 GHz | 0.15 dB max. |
| ETC0196 | 1.93–1.99 GHz | 0.17 dB max. |
| ETC0185 | 1.805–1.885 GHz | 0.18 dB max. |
If bandwidth is more important, the ETCE series trades a small increase in insertion loss for wider frequency coverage.
4. Check Isolation and VSWR
Isolation helps prevent reflected energy from returning toward sensitive RF stages.
Nova's narrowband ETC products generally provide 22–23 dB minimum isolation, while ETCE models are typically specified at 21 dB minimum isolation.
VSWR is also important because poor matching can increase reflected power and reduce overall RF system efficiency.
Typical maximum VSWR values include:
1.15:1 for selected narrowband ETC models
1.18:1 for models such as ETC0175, ETC0240 and ETC0260
1.20:1 for ETCE wideband models
Typical Applications
Nova Microwave high-power low-loss circulators can be considered for:
RF power amplifier output stages
Wireless base stations
Cellular infrastructure
RF transmitter systems
Radar transmitters
Communication systems
High-power RF test equipment
Antenna and duplexing systems
The actual model should be selected according to frequency, continuous and peak RF power, reflected power, thermal conditions and mechanical integration requirements.
Frequently Asked Questions
Which Nova Microwave circulator has the lowest insertion loss?
Several models, including ETC0215, ETC0240 and ETC0260, specify maximum insertion loss of 0.15 dB within their respective frequency bands.
Which Nova Microwave circulator is suitable for 2.4 GHz and 250 W?
ETC0240 is a strong candidate for 2.3–2.5 GHz applications requiring up to 250 W forward power. For wider 2.4–2.7 GHz coverage, ETCE0255 may be more suitable.
What is the difference between ETC0240 and ETCE0255?
ETC0240 covers a narrower 2.3–2.5 GHz band but provides lower insertion loss of 0.15 dB. ETCE0255 covers the wider 2.4–2.7 GHz range with maximum insertion loss of 0.21 dB. Both support up to 250 W forward power.
Should I choose an ETC or ETCE circulator?
Choose an ETC model when minimum insertion loss and performance over a narrower band are the main priorities. Choose an ETCE model when wider operating bandwidth is more important.
Need Help Selecting a High-Power Nova Microwave Circulator?
DataStorageIC supplies Nova Microwave circulators and isolators for high-power RF, wireless, radar and microwave applications.
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