Tech Chat | Should I Choose A Choke Ring Antenna For My Reference Station?

-04-11

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After the release of our SV100 GNSS receiver six months ago, we've received substantial interest and positive feedback from users. Many have adopted the SV100 for reference stations in their CORS or monitoring endeavors.

One of the most common queries we've encountered while assisting our SV100 users in establishing reference stations is whether a choke ring antenna would be beneficial for the SV100. What advantages does a choke ring antenna offer compared to a standard geodetic antenna?

Today’s blog aims to provide a concise overview of the choke ring antenna to support your decision-making process.

What Is Choke Ring Antenna?

Choke ring antennas have been widely recognized for their ability to minimize the impact of multipath signals. They consist of a circular arrangement with several slots or gaps that function as waveguides, effectively canceling out reflected signals. Typically made from conductive materials like metal, these antennas are positioned above a ground plane to diminish interference.

A choke ring antenna is specifically crafted to mitigate multipath interference. It is generally one-quarter wavelength deep, forming a high impedance surface that prevents surface wave propagation near the antenna while curtailing undesired excitation modes. This design yields a smooth and controlled signal pattern with reduced susceptibility to multipath effects.

What Is Multipath Interference?

Multipath interference occurs when satellite signals reflect off surfaces, such as buildings or vehicles, arriving at the antenna at varying times, which leads to inaccuracies in GNSS measurements.

When GNSS signals approach the choke ring antenna, they traverse through the gaps in the rings, reaching the antenna element directly. Reflected signals are obstructed by the rings, preventing them from being captured. This ensures that the signals detected are predominantly direct signals from GNSS satellites, thereby enhancing positioning accuracy.

Consequently, choke ring antennas are prevalent in high-precision GNSS applications, significantly minimizing multipath errors in national CORS and extensive monitoring projects.

Is the Choke Ring Antenna Essential?

Though choke antennas are popular, a smaller variant of GNSS antenna, known as the geodetic antenna, can also serve reference stations. Feedback from the market indicates it performs well and is worthy of recommendation.

Choke ring antennas are generally seen as more advanced than geodetic antennas, but they come with a steep price—usually four to five times more expensive than their geodetic counterparts.

In summary, if you possess a considerable budget and aim to create a professional CORS network, the choke ring antenna is the optimal choice. However, if your goal is personal use without rigorous project standards, geodetic antennas offer a cost-effective alternative.

SingularXYZ SA100 Geodetic Antenna and SA500 Choke Ring Antenna are available now to cater to your specific requirements.
SA500 Choke Ring Antenna
SA100 Geodetic Antenna

Description

Choke Ring Full Band Antenna Description:

This is a four-star full-frequency reference station antenna boasting high gain and precision. It is compatible with multiple systems and offers exceptional reliability. The antenna is suitable for geodetic surveying, mapping, and precision agriculture.

Passive Antenna Performance

Frequency:

Beidou B1/B2/B3

Galileo E1/E2/E5a/E5b

Glonass G1/G2

GPS L1/L2/L5

Peak Efficiency

46%

49%

Polarization

RHCP

Realized Gain

6dB

Axial Ratio

Max 3 dB at the Zenith

VSWR

Max 2:1

Beamwidth

10-90°

Horizontal Coverage

0-360°

RF Specifications

• LNA Gain: 50 dB
• Noise Figure: 1.5 dB typical, 2 dB max
• Axial Ratio: 3 dB
• Phase center error: +/- 2mm
• Voltage: 3.3 to 12 V
• Current: 50 mA max
• Flatness in Band: +/-2dB
• Differential delay: +/- 2nS

Choke Ring Full Band Antenna Features:

Contact us to discuss your requirements for the Full Frequency 3D Choke Ring Antenna. Our experienced sales team can assist you in identifying the best options for your needs.

• Concurrent GNSS reception on GPS, GLONASS, Galileo, and Beidou
• Rugged IP67 rating with TNC-K mount
• Dome form factor
• Applicable for GIS, RTK, and other high-accuracy GNSS uses
• Low power consumption
• Low phase center variation over azimuth and elevation and among different samples
• TNC-K to SMA 5m cable included
• Dimension: 380 x 296 mm