Cdsenet TX433-TH-3 433MHz Spring Antenna 1.0 dBi Gain PCB Mount

Compact Helical Spring Design for Space-Constrained Applications

The TX433-TH-3 features a precision-wound helical coil construction that compresses the antenna's electrical length into a compact 30mm physical height, making it ideal for space-constrained PCB designs and portable devices. The spring design provides omnidirectional radiation pattern with consistent performance across all horizontal directions. The copper wire construction with tin plating ensures excellent conductivity and corrosion resistance, while the flexible spring structure offers mechanical shock absorption and vibration resistance, critical for mobile and handheld applications.

Direct PCB Soldering Interface for Easy Integration

The antenna features a wire lead termination designed for direct soldering to PCB pads or through-hole mounting, eliminating the need for bulky connectors and reducing overall system cost. The 0.5mm (AWG 24) tinned copper wire provides reliable electrical contact and mechanical stability when properly soldered. This interface is particularly suitable for high-volume manufacturing where automated pick-and-place and wave soldering processes are used. The antenna maintains 50¦¸ impedance matching when mounted vertically on a properly designed ground plane (minimum 40mm ¡Á 40mm recommended).

Verified using professional RF test equipment at 433 MHz center frequency: VSWR measured consistently ¡Ü 1.5 across the ISM band (433.05-434.79 MHz), ensuring efficient power transfer and minimal reflected energy. Return loss (S11) exceeds -14 dB throughout the operational bandwidth, confirming excellent impedance matching to 50¦¸ systems. The omnidirectional radiation pattern provides consistent coverage with gain variation less than ¡À2 dB across the horizontal plane, ideal for applications requiring uniform signal distribution.

(Complete VSWR / S11 / radiation pattern measurements available upon request)

Q: How do I properly solder this antenna to my PCB?

A: The TX433-TH-3 features a tinned copper wire lead designed for through-hole or surface-mount soldering. For optimal performance, mount the antenna vertically (perpendicular to the PCB) and solder the wire lead to a PCB pad connected to your RF transceiver's antenna output via a 50¦¸ transmission line. Ensure a proper ground plane (minimum 40mm ¡Á 40mm) is present on the PCB to serve as the antenna's counterpoise. Use standard lead-free solder (SAC305) at 350-370¡ãC with a soldering time of 2-3 seconds to avoid thermal damage to the spring coil. Avoid excessive mechanical stress during soldering to prevent detuning.

Q: What is the expected range with this antenna?

A: Communication range depends on transmitter power, receiver sensitivity, modulation scheme, and environmental conditions. With a typical 10mW (10dBm) 433MHz transmitter and -110dBm receiver sensitivity, expect line-of-sight range of 100-300 meters in open areas. The 1.0 dBi gain provides approximately 1.25x range improvement compared to a 0 dBi reference antenna. Indoor range will be significantly reduced (20-50 meters) due to wall attenuation and multipath interference. For extended range, consider higher transmit power (within regulatory limits of 10mW ERP in Europe, 1W in USA) or using higher-gain external antennas.

Q: Is this antenna suitable for outdoor applications?

A: The TX433-TH-3 is designed primarily for indoor or protected outdoor applications. The tin-plated copper wire provides basic corrosion resistance and operates reliably across -40¡ãC to +85¡ãC temperature range. However, for harsh outdoor environments with direct weather exposure, we recommend enclosing the antenna in a weatherproof enclosure with a radome (plastic cover) to protect against moisture, UV degradation, and physical damage. The antenna is RoHS compliant and suitable for consumer and industrial applications. For permanent outdoor installations, consider our weatherproof external antenna options with IP67-rated connectors.

Q: Can I use this antenna with LoRa modules operating at 433MHz?

A: Yes, the TX433-TH-3 is fully compatible with 433MHz LoRa modules (SX1276, SX1278, SX1262 transceivers) and other modulation schemes (FSK, GFSK, OOK, ASK) operating in the 433MHz ISM band. The antenna's 50¦¸ impedance matches standard LoRa module RF outputs, and the VSWR ¡Ü1.5 ensures efficient power transfer across the LoRa bandwidth (typically 125-500 kHz). For optimal LoRa performance, ensure proper PCB layout with adequate ground plane, minimize trace length between the module and antenna, and consider adding a ¦Ð-network or LC matching circuit if VSWR optimization is required for your specific PCB layout.

Q: What PCB design considerations are important for this antenna?

A: For optimal performance, follow these PCB design guidelines: (1) Provide a solid ground plane of at least 40mm ¡Á 40mm on the PCB layer directly beneath the antenna mounting point. (2) Mount the antenna vertically at the edge or corner of the PCB to maximize omnidirectional coverage. (3) Keep the antenna at least 10mm away from metal enclosures, batteries, and other RF-sensitive components. (4) Use a 50¦¸ microstrip or coplanar waveguide transmission line to connect the antenna feed point to your RF module, keeping trace length below 20mm to minimize losses. (5) Avoid routing digital signals or power traces near the antenna feed to prevent RF interference. (6) Consider adding a ¦Ð-network (series inductor + shunt capacitors) for fine-tuning impedance matching if needed. Reference application notes from your RF module manufacturer for specific layout recommendations.