Helical antennas can be used for multiple GNSS bands. Yes, if those bands are in its operating range. The AH-1117-11 operates between 1100 and 1700 MHz. That's a 600 MHz span with a typical gain of 11 dBic. It includes the GPS L1, L2 and L5 center frequencies.

Another common question buyers ask when choosing a high-gain helical antenna manufacturer in India is whether one antenna can cover the functions of three separate antennas. The answer depends on the band, the gain, the polarisation and the mounting. In this blog, I will refer to the published AH-1117-11 Helical Antenna datasheet for each point.

Why 1100–1700 MHz Matters for GNSS Ground Work

GNSS signals are located in the L-band. According to a GPS.gov fact sheet, L1 is 1575.42 MHz, L2 is 1227.6 MHz and L5 is 1176.45 MHz. All three are in the AH-1117-11 range.

Other systems float close by. Rohde & Schwarz lists Galileo at 1575.42, 1278.75, 1207.14 and 1176.45 MHz. BeiDou operates at 1561.098, 1575.42, 1268.52, 1207.14 and 1176.45 MHz. GLONASS G1 and G2 are about 1602 and 1246 MHz. All of these center frequencies lie within the span.

Although the 1100–1700 MHz range includes several GNSS frequencies, our datasheet specifically identifies GPS bands L1, L2, L5, and L6 as supported signals. A center frequency somewhere in the span does not mean flat gain or clean circular polarisation at that very signal.

One directional L-band helical antenna can serve several signals on a ground station. Test engineers can change bands but keep the same antenna in a range. Ask us for the radiation pattern at the frequencies you want.

Extended Stubs: More Gain Without Going Too Narrow

The axial-mode helix is governed by a simple rule. More turns increase gain and narrow the beam width. Gain and beamwidth are opposing forces.

The AH-1117-11 uses extended stubs for more gain and wider beamwidth, as specified in our datasheet. Take this as a design goal. More gain does not mean more coverage. This antenna is still directional with 11 dBic. You still need to point it out.

So look at the half power beamwidth versus how accurately you can point. A wider beam allows for small pointing errors. A tighter one needs more steady steering.

RHCP or LHCP: Matching the Link

Circular polarisation twists the signal’s electric field in a corkscrew. Right-hand circular polarisation (RHCP) and left-hand circular polarisation (LHCP) describe opposite directions of rotation in the electric field.

Both versions of the AH-1117-11 are available. AH-1117-11-R is RHCP, and AH-1117-11-L is LHCP. 7. The datasheet headline is for the RHCP model. GNSS satellites transmit right-hand circular polarisation. So RHCP is the usual recipient of them. Match whatever the other end uses for a link to another ground or airborne system.

Our datasheet also says circular polarisation reduces multipath interference.

Steering, Radome and Stacking Options

The antenna also includes a mounting arrangement which allows it to be steered over 360 degrees in azimuth and 90 degrees in elevation. Fits mast pipes up to 52mm.

An ABS cylindrical radome protects the helix. The shape reduces wind loading and minimizes the impact of ice on performance, according to the data sheet. We don’t quote figures for wind or ice here. Ask our team for the current rating before sizing a mast.

Counter-drone installations can operate in challenging environments, including locations exposed to sand and strong winds. These conditions make suitable radome protection and secure antenna mounting important. Challenges the military expects such systems to face included sand and wind. And that doesn’t include our antenna. It does show why enclosure and mounting choices matter.

For more gain, we can provide dual- or quad stacked arrays with power splitter and combiner harness. Stacking has its limits. In theory each doubling can add up to about 3 dB . Some is lost in splitter and cable losses. Also the beam narrows. You have to allow for phase matched cables and spacing. The mast carries more load as well.

• 9, 11, 13 and 16 dBic Variants

The AH-1117 series covers the same 1100-1700 MHz range in four gain steps:

• AH-1117-9: 9 dBic
• AH-1117-11: 11 dBic
• AH-1117-13: 13 dBic
• AH-1117-16: 16 dBic

The AH-1117-11 is the 11 dBic version. The higher the gain, the longer the antenna and the narrower the beam. For low gain all round coverage look at a Quadrifilar Helix Antenna such as the QHA-1117 at 2 dBic.

Helix vs Yagi Size

The shape of the helix results in circular polarisation. A Yagi is typically linear. Yagis need crossed elements and phases to radiate in a circle. Coupling a circular antenna to a linear antenna costs about 3 dB. In our data sheet we say that the AH series is smaller than a conventional Yagi. A Yagi is suitable for a fixed linear link. Not all designs get hired. Choose according to link polarisation and space and pointing accuracy.

How Antenna Experts provides AH-1117 Series

We produce helical antennas and are open to specification requests from buyers. We are the manufacturer of high gain helical antennas in India. We provide the AH-1117 series in RHCP and LHCP Versions with stacked options. The series is also listed in our GPS Jammer Anti-Jam Antenna category. Other bands are available in the full High Gain Helical Antenna range.

• Figures from AH-1117-11 datasheet:
• Frequency: 1100-1700 MHz
• Gain: 11 dBi typical
• Impedance: 50 Ohms VSWR: 2:1 or better
• Connector: N-female
• Radome: ABS and gross weight less than 2.5 kg

As a High Gain Helical Antenna manufacturer in India, we invite you to send us your band list, polarisation and target gain to begin. Include mast details as well. We will share the datasheet and available documents, such as radiation patterns and VSWR curves.

GNSS band transmission and jamming rules vary across countries. Check local law and licensing prior to use. We cannot guarantee approvals or procurement results.

Why Choose Antenna Experts?

If you are shortlisting a manufacturer of best High Gain Helical Antenna in India, ask for numbers that you can check. Antenna Experts is a dedicated antenna manufacturer and supplier company in India. We share model-specific gain specifications and distinguish published datasheet values from general antenna design principles.

• The gain value is different in each model. We don't mix them.
• We distinguish datasheet facts from general antenna principles.
• It is available in both polarisation and stacked array form.
• Pattern and VSWR documentation is available on request.

Frequently Asked Questions

1.     What frequency ranges does the AH-1117-11 cover? 

It covers 1100 to 1700 MHz. These include the GPS L1, L2 and L5 center frequencies.

2.                What is the gain for AH-1117-11? 

Typical gain: 11 dBi. The 9, 13 and 16 dBic are for other models of AH-1117. 

3.                Can you stack helical antennas for more gain? 

Yes. We can supply dual or quad stacked arrays with a splitter/combiner harness. Losses and narrower beams are relevant.

About the Author 

Kajal Singh, Marketing Manager at AntennaExperts.com. Her focus is antenna solutions, RF communications and defence and aviation applications for engineering and procurement audiences.