This document describes a dual-antenna system for a video-recording doorbell and associated devices and systems. The described antenna system may be implemented on an elongated printed circuit board and can be used for wideband and ultra-wideband applications. For low-cost devices, the dual-antenna system may implement diversity antennas by including first and second substantially orthogonal antennas connected to a chipset configured for single-input single-output (SISO) functionality. The dual-antenna system described herein achieves high antenna isolation and efficiency without a decoupling structure between the first and second antennas. Further, the dual-antenna system achieves high isolation while in proximity to a battery (e.g., a battery within a housing of a battery-powered, video-recording doorbell) and a metal plate for mounting the device to a wall or other structure.