Planar antennas, including microstrip, printed, metal-plate, ceramic chip, and dielectric resonator antennas, are flat and low-profile. They have found significant applications in mobile systems (e.g., 900/1800 MHz bands), wireless local area networks (WLANs, e.g., 2.4/5.2/5.8 GHz bands), and ultra-wideband (UWB, e.g., 3.1 ~ 10.6 GHz band) communications. Recent developments in planar antenna designs for internal mobile phones, base stations, WLAN mobile units, access points, and UWB antennas are discussed, along with techniques for achieving high antenna performance. In recent years, wireless technologies have evolved to eliminate wire links in commercial products like computers, digital cameras, and TVs. Key design considerations include low power consumption, high integration, high efficiency, and high system throughput. While quadrature modulation-based transmitters are widely used, constant envelope modulations (e.g., GFSK, GMSK) offer advantages. These modulations can be directly modulated using frequency synthesizers without mixers, leading to modulated frequency synthesizers. This tutorial covers the latest modulated frequency synthesizers for wireless transmitter applications, including an overview of modern RF transmitter architectures and several types of modulated frequency synthesizers, with a focus on two-point delta-sigma modulation (TPDSM) for its wideband characteristics.Planar antennas, including microstrip, printed, metal-plate, ceramic chip, and dielectric resonator antennas, are flat and low-profile. They have found significant applications in mobile systems (e.g., 900/1800 MHz bands), wireless local area networks (WLANs, e.g., 2.4/5.2/5.8 GHz bands), and ultra-wideband (UWB, e.g., 3.1 ~ 10.6 GHz band) communications. Recent developments in planar antenna designs for internal mobile phones, base stations, WLAN mobile units, access points, and UWB antennas are discussed, along with techniques for achieving high antenna performance. In recent years, wireless technologies have evolved to eliminate wire links in commercial products like computers, digital cameras, and TVs. Key design considerations include low power consumption, high integration, high efficiency, and high system throughput. While quadrature modulation-based transmitters are widely used, constant envelope modulations (e.g., GFSK, GMSK) offer advantages. These modulations can be directly modulated using frequency synthesizers without mixers, leading to modulated frequency synthesizers. This tutorial covers the latest modulated frequency synthesizers for wireless transmitter applications, including an overview of modern RF transmitter architectures and several types of modulated frequency synthesizers, with a focus on two-point delta-sigma modulation (TPDSM) for its wideband characteristics.