This work aims to explore novel ideas and architectures to implement flexible, high-efficiency load modulated amplifiers. A set of versatile closed-form equations, termed VIP equations, is derived for analyzing active N-port networks. These equations are applicable to a wide range of issues, including load modulation (LM) in amplifiers and mutual coupling in MIMO systems. To illustrate the use of these equations, they are applied to several conventional LM structures such as Doherty and loadmodulated balanced amplifier (LMBA), enabling broader design space exploration. Based on this foundation, and highlighting another innovative application of the VIP equations, a novel load modulated architecture, termed Tri-Coupled-Line Amplifier (TCLA), featuring a three-coupled-line combiner, is proposed and analyzed. This architecture offers significant advantages, including enhanced back-off efficiency, while maintaining simplicity in design and implementation. The output back-off equation of TCLA is equivalent to conventional Doherty, with efficiency characteristics close to three-way Doherty and Sequential-LMBA (SLMBA), but without the overdrive challenges associated with SLMBA. To concept proof, the TCLA prototype with 45 dBm power at 2.4 GHz and %60 efficiency at 8 dB output back-off (OBO) was designed and implemented.