Quick Answer
RHCP (Right-Hand Circular Polarised) and LHCP (Left-Hand Circular Polarised) are the two directions radio waves spiral from a circular polarised FPV antenna. RHCP is the FPV community standard. LHCP performs identically but is rarely used on its own. The golden rule: your VTX and goggle antennas must be the same polarisation. Mismatched polarisation causes 15-20dB signal loss, turning a 600mW VTX into what looks like 6mW.
What Is Circular Polarisation?
Antenna polarisation describes the orientation of radio waves as they travel through the air. For FPV video at 5.8GHz, circular polarisation is the dominant standard. Instead of radiating in a flat plane (linear), circular polarised antennas transmit in a spiral pattern, rotating either clockwise (RHCP) or anticlockwise (LHCP). Think of it like a corkscrew turning in one of two directions.
The key advantage is multipath rejection. When your video signal bounces off buildings, trees, or the ground, those reflections reverse polarisation. A circular polarised antenna rejects the reversed reflections because its spiral pattern does not match. This is why circular polarised antennas hold a cleaner picture through obstacles than linear antennas, which receive reflections at full strength.
RHCP vs LHCP vs Linear: Comparison Table
| Property | RHCP | LHCP | Linear |
|---|---|---|---|
| Wave rotation | Clockwise (right-hand) | Anticlockwise (left-hand) | Flat plane, no rotation |
| FPV standard? | Yes, community default | No, specialist use only | No (stock whip antennas only) |
| Multipath rejection | Excellent | Excellent | Poor, reflections cause ghosting |
| Mismatch loss | 15-20dB vs LHCP | 15-20dB vs RHCP | 3dB vs perpendicular linear |
| Typical use | All outdoor FPV | Race frequency management, indoor | Stock whoop antennas, budget kits |
| Performance difference | Identical to LHCP | Identical to RHCP | Worse through obstacles |
RHCP and LHCP perform identically in every measurable way. The spiral direction makes zero difference to range, clarity, or penetration. We stock the TrueRC Singularity stubby in both polarisations, but RHCP accounts for nearly every unit we sell. Choose LHCP only if you fly at events where frequency management requires opposite polarisation to separate adjacent pilots.
What Is LHCP?
LHCP stands for Left-Hand Circular Polarised. The radio wave spirals anticlockwise as it travels away from you. LHCP exists not because it performs differently, but because it provides a second channel of isolation. At organised races where multiple pilots fly simultaneously, RHCP and LHCP antennas let two pilots on the same frequency fly without interfering, because cross-polarisation rejection prevents their signals from bleeding into each other's goggles.
For solo flying or small group sessions, there is no practical reason to use LHCP. Stick with RHCP for maximum compatibility with spare antennas and loaner goggles.
How to Identify Your Antenna Polarisation
If your antenna is not clearly labelled, you can determine polarisation visually. Hold the antenna with the lobes facing you and the connector pointing down. Look at the curve of the lobes:
- RHCP: Lobes curve to the right from bottom to top (clockwise)
- LHCP: Lobes curve to the left from bottom to top (anticlockwise)
- Linear: A single straight wire element, no curved lobes
Most circular polarised antennas (cloverleaf, pagoda, mushroom) have three or four lobes. If there is no marking and you cannot tell, assume RHCP. That is the FPV default and correct for 90% of setups. The TrueRC Matchstick and most quality antennas are etched with "RHCP" or "LHCP" on the connector barrel.
Polarisation Mismatch: The 20dB Penalty
When your VTX and receiver antennas use opposite polarisation, the spiral patterns rotate against each other. The result is severe signal loss, typically 15-20dB. In practical terms, a 600mW VTX with mismatched polarisation performs like 6mW. You will see heavy static, dropouts, or complete signal loss at ranges where it was previously crystal clear.
This is the easiest FPV problem to diagnose. If video suddenly degrades at a range that worked before, check both antennas. Most are marked with RHCP or LHCP near the connector. Swap in a matched pair and your signal returns immediately.
Mixing circular with linear is less catastrophic but still suboptimal. A circular VTX antenna into a linear goggle antenna loses about 3dB (half your effective power). Many stock whoop kits ship with linear whip antennas on both ends, which works fine at close range but will not penetrate obstacles like a circular pair.
Which Antennas We Recommend
Polarisation is only one factor. Build quality, gain, and beam width matter more. For a 5-inch freestyle or racing build, we recommend a FlyFishRC Osprey 60mm RHCP on the VTX for durability and a TrueRC Singularity stubby on the goggles for crash resistance. The TBS Unify Pro 5G8 pairs well with any quality RHCP antenna.
For long-range flying, consider a directional patch antenna on your goggles and an omnidirectional cloverleaf on the drone. Browse our antennas collection for the full range, and see our complete antenna buying guide for a deeper dive.
FAQ
Q: Can I mix RHCP and LHCP antennas?
A: No. Mixing polarisation types causes 15-20dB signal loss. A 600mW VTX performs like 6mW. Always match your VTX and goggle antennas to the same polarisation.
Q: What is the difference between RHCP and LHCP?
A: The direction the radio wave spirals. RHCP rotates clockwise, LHCP rotates anticlockwise. Performance is identical. RHCP is the FPV community standard. LHCP is used mainly at organised races for frequency management.
Q: What does LHCP mean?
A: Left-Hand Circular Polarised. The radio wave spirals anticlockwise away from the antenna. It performs identically to RHCP but is rarely used outside of race events where pilots need polarisation isolation.
Q: Which polarisation is better for racing?
A: RHCP is the standard for outdoor FPV racing. Nearly all racing VTXs, receivers, and antennas ship as RHCP. Use LHCP only if race organisers assign it for frequency management.
Q: How do I tell if my antenna is RHCP or LHCP?
A: Hold it with lobes facing you and connector down. If lobes curve right (clockwise), it is RHCP. If they curve left (anticlockwise), it is LHCP. If there is no marking, assume RHCP, the FPV default.
Q: Can I use a linear antenna with a circular polarised one?
A: You can, but you lose about 3dB (half your effective power). It works at close range but will not reject multipath interference. Replace linear stock antennas with circular ones for better video through obstacles. For more on antenna types, see our connector guide and gain explainer.