ANT-433-HETH Data Sheet by Product Description HE Series antennas are designed for direct PCB 8.89 mm Outside mounting. Thanks to the HE’s compact size, they Diameter (0.35") are ideal for internal concealment inside a product’s housing. The HE is also very low in cost, making it well suited to high-volume applications. HE Series Inside 6.4 mm Diameter (0.25") antennas have a very narrow bandwidth; thus, care in placement and layout is required. In addition, they are not as efficient as whip-style antennas, so they are generally better suited for use on the transmitter end where attenuation is often required Wire 15.24 mm Diameter (0.60") anyway for regulatory compliance. Use on both 1.3 mm transmitter and receiver ends is recommended only (0.05") 6(0..3255 "m)m in instances where a short range (less than 30% of whip style) is acceptable. 38.1 mm (1.50") Features • Very low cost Recommended Mounting • Compact for physical concealment • Precision-wound coil No ground plane or traces No electircal • Rugged phosphor-bronze construction under the antenna connection on this • Mounts directly to the PCB pad. For physical 38.10 mm support only. (1.50") Electrical Specifications Center Frequency: 433MHz 7.62 mm 1.52 mm (Ø0.060") Recom. Freq. Range: 418–458MHz (0.30") 3.81 mm Wavelength: ¼-wave 12.70 mm (0.15") (0.50") VSWR: ≤ 2.0 typical at center Peak Gain: 1.9dBi Impedance: 50-ohms Connection: Through-hole Oper. Temp. Range: –40°C to +80°C Electrical specifications and plots measured on a 7.62 x 19.05 Ground plane on cm (3.00" x 7.50") reference ground plane 50-ohm microstrip line bottom layer for counterpoise Ordering Information ANT-433-HETH (helical, through-hole) – 1 – Revised 5/16/16

Counterpoise Quarter-wave or monopole antennas require an associated ground plane counterpoise for proper operation. The size and location of the ground plane relative to the antenna will affect the overall performance of the antenna in the final design. When used in conjunction with a ground plane smaller than that used to tune the antenna, the center frequency typically will shift higher in frequency and the bandwidth will decrease. The proximity of other circuit elements and packaging near the antenna will also affect the final performance. For further discussion and guidance on the importance of the ground plane counterpoise, please refer to Linx Application Note AN-00501: Understanding Antenna Specifications and Operation. VSWR Graph VSWR 1.438 Reflected Power 3:1 25% 2:1 11% 1:1 0% 333MHz 433MHz 533MHz What is VSWR? The Voltage Standing Wave Ratio (VSWR) is a measurement of how well an antenna is matched to a source impedance, typically 50-ohms. It is calculated by measuring the voltage wave that is headed toward the load versus the voltage wave that is reflected back from the load. A perfect match will have a VSWR of 1:1. The higher the first number, the worse the match, and the more inefficient the system. Since a perfect match cannot ever be obtained, some benchmark for performance needs to be set. In the case of antenna VSWR, this is usually 2:1. At this point, 88.9% of the energy sent to the antenna by the transmitter is radiated into free space and 11.1% is either reflected back into the source or lost as heat on the structure of the antenna. In the other direction, 88.9% of the energy recovered by the antenna is transferred into the receiver. As a side note, since the “:1” is always implied, many data sheets will remove it and just display the first number. How to Read a VSWR Graph VSWR is usually displayed graphically versus frequency. The lowest point on the graph is the antenna’s operational center frequency. In most cases, this will be different than the designed center frequency due to fabrication tolerances. The VSWR at that point denotes how close to 50-ohms the antenna gets. Linx specifies the recommended bandwidth as the range where the typical antenna VSWR is less than 2:1. 159 Ort Lane, Merlin, OR, US 97532 Phone: +1 541 471 6256 Fax: +1 541 471 6251 – 2 – Data Sheet ANT-433-HETH www.linxtechnologies.com by

Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: L inx Technologies: ANT-433-HETH