Directional light manipulation plays an important role in the optical link and communication of nanotechnology and modern optics. In this work, we provide a practical solution for directional radiation based on drastic slow light resonance near the photonic band-edge. Unidirectional stretched oscillations in the modified resonator almost completely suppress both longitudinal reflected and leaky losses to guarantee transverse scatterings with high directivity. The scaling invariance and flexible tunability of photonic crystal enable it to operate with relaxed structural parameters from infrared to microwaves. Microwave experiments have demonstrated the energy transfer and directional radiation process, agreeing well with the theoretical results. The iconic advantages of high transfer efficiency > 90%, far better directivity gain, 3db splitting, and flexible tunability make photonic crystal (PhC)-resonators promising for advanced application in the wireless link, filtering, and sensing of micro-nano integrated circuits.