| Operating Frequency | Minimum and maximum supported frequencies | Select an antenna whose tested frequency range fully covers the required bands, such as VHF, UHF, cellular, GNSS, Wi-Fi, or public-safety bands. | A wider nominal range does not guarantee consistent performance across every frequency. | Review the manufacturer’s measured performance plots and test conditions. |
| Bandwidth | Absolute bandwidth and fractional bandwidth | Fractional bandwidth is commonly expressed as: 2(fH − fL) / (fH + fL) × 100%. | Fractional bandwidth allows fair comparison between antennas operating at different frequency ranges. | Calculate the percentage from the published lower and upper frequency limits. |
| Impedance | Nominal input impedance and stability over frequency | 50 Ω is the standard impedance for most wireless systems and coaxial RF equipment. | Impedance compatibility helps minimize reflections and power loss. | Confirm the impedance specification and measure the installed antenna with a calibrated VNA. |
| VSWR / Return Loss | VSWR limit or return-loss value across the required bands | A VSWR of ≤2.0:1 is a common system-level target; lower values provide more margin. Return loss of approximately ≥9.5 dB corresponds to VSWR of 2.0:1. | Lower mismatch reduces reflected power and improves transmitter-to-antenna power transfer. | Check measured VSWR or S11 graphs at the actual installation location. |
| Gain | Gain at each required frequency and the measurement reference | Wideband blade antennas often provide approximately 0 to 6 dBi, depending on size, frequency, and installation. | Gain affects coverage, link margin, and received signal strength. | Compare measured gain plots rather than relying only on a single peak-gain figure. |
| Radiation Pattern | Azimuth coverage, elevation pattern, nulls, and pattern stability | A vertically mounted blade is generally selected for near-omnidirectional horizontal coverage. | The physical platform and nearby metal can distort the pattern and create coverage gaps. | Review 2D and 3D radiation-pattern plots for the intended mounting arrangement. |
| Polarization | Linear polarization direction and polarization purity | Vertical linear polarization is common for terrestrial mobile and land-based radio applications. | Polarization mismatch can significantly reduce the received signal. | Match the antenna orientation to the transmitting system and verify the installation drawing. |
| Power Handling | Continuous-wave power, peak power, and duty cycle | Choose a rating above the transmitter’s maximum output, including duty-cycle and mismatch conditions. | Insufficient power capacity may cause heating, arcing, or permanent damage. | Check the power rating at each operating band, not only the maximum headline value. |
| Physical Dimensions | Height, width, ground-plane requirements, and installation envelope | Compact blade designs may be roughly 100–500 mm tall, but dimensions vary substantially with frequency coverage. | Size affects low-frequency efficiency, wind loading, visual clearance, and mechanical fit. | Compare the full mechanical drawing, clearance zone, and required conductive mounting surface. |
| Connector and Cable | Connector type, cable length, cable loss, and sealing method | Common RF connectors include N-type, TNC, SMA, and UHF types; selection depends on frequency, space, and environment. | A connector or cable with inadequate frequency rating can degrade the complete RF link. | Verify connector compatibility, cable attenuation, bend radius, and waterproofing details. |
| Environmental Protection | Ingress protection, operating temperature, humidity, salt spray, and UV resistance | For outdoor use, look for a documented IP rating, such as IP65 or higher, together with an appropriate temperature range. | Moisture, corrosion, and temperature cycling can change impedance and shorten service life. | Review environmental test standards, enclosure rating, and material specifications. |
| Mechanical Strength | Wind speed, vibration, shock, mounting torque, and material strength | Select a design whose documented wind and vibration ratings exceed the site requirements with a safety margin. | Mechanical movement can detune the antenna or cause fatigue at the mounting point. | Check structural test data, mounting hardware, and installation torque requirements. |
| Grounding and Mounting | Ground-plane dependence, bracket type, bonding, and lightning protection | Some blade antennas require a conductive ground plane, while others are designed for specific vehicle, mast, or wall mounts. | Incorrect mounting can change VSWR, gain, radiation pattern, and safety performance. | Use the recommended mounting configuration and bond the system according to applicable electrical codes. |
| Size, Weight, and Cost | Total installed weight, lifecycle cost, maintenance, and replacement requirements | Prioritize the lowest total installed cost that meets RF, structural, environmental, and certification requirements. | The least expensive antenna may require additional brackets, cables, filters, or maintenance. | Compare the complete bill of materials and expected service life rather than purchase price alone. |