# Directly Matching an MMIC Amplifier Integrated with MIMO Antenna through DNNs for Future Networks
## 5 Conclusions  
The linearity specification is a crucial aspect in the communication systems where optimization of this outcome is not straightforward and requires substantial efforts. For the very first time in the literature, we present a novel methodology for concurrently optimizing active and passive devices leading to enhanced overall performance. In this study, we design MIMO antenna with MMIC design as passive and active devices, respectively. Firstly, the antenna is modeled through DNN which forecasts the impedances that can be directly matched to the drain impedance of a used transistor at large bandwidth. Afterwards, the MMIC design, a class AB amplifier, is modeled through the DNN where it is optimized with respect to the predicted impedances through modeled antenna. In the second DNN, the multivariate newton's method is employed, enabling us to optimize the linearity specification of overall system. To prove the novelty of the proposed method, MMIC design with MIMO antenna are concurrently designed and optimized in the frequency band of 7.49 GHz to 12.44 GHz. Our proposed methodology can be developed by: (1) considering various types of neural networks, (2) using more reliable transistor models in the MMIC designs, (3) altering the feeding points of the antenna, (4) considering the non-orthogonal multiple access (NOMA) scheme for 5G networks, (5) further investigating the effect of antenna coupling on the PAs.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Acknowledgments:** The author would like to express her appreciation for the grant of [PERSON], provided by the IEEE.  
**Conflicts of Interest:** The author has no conflict of interest.  
\begin{table}
\begin{tabular}{p{42.7 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Ref.** & **Method** & **Goal(s) of Paper** \\ \hline
[16] & Balancing multiport feeding of the cavity-backed patch antenna & - Providing the optimal loading conditions for doherty PA \\ \hline
[17] & PA-aware precoding method by convex optimization & - Exploiting the high-dimensional degrees of freedom: - Enhancing transmission quality \\ \hline
[18] & Coherent and non-coherent beamforming consideration & - Maximizing the energy efficiency \\ \hline
[19] & ANN-based optimization & - Optimizing the radiation and nonlinear performances \\ \hline
[20] & Nonlinear loadpull simulations & - Maximizing efficiency and bandwidth \\ \hline
[21] & Iterative procedure & - Optimizing radar performance in signal-dependent interference \\ \hline
[22] & Analytical expressions for the nonlinear distortion & - Enhancing resource allocation problem \\ \hline
[23] & Saleh PA-model for nonlinearity and the large scale satellite channel parameters & - Maximizing the achievable rate of the satellite system \\ \hline
[24] & Successive convex approximation & - Considering the capacity of the MIMO channel \\ \hline
[25] & Methodology based on the signal-to-noise ratio & - Optimizing energy Efficient \\ \hline This work & Two LSTM-based DNNs with Multivariate Newton’s Method & - Modeling of antenna and amplifier through LSTM-based DNNs: - Predicting the extended impedance over the large bandwidth; - Achieving the optimal drain impedances: - Enhancing the linearity specification of the overall system. \\ \hline \hline \end{tabular}
\end{table}
Table 4: Summary of various methodologies employed for hybrid design of antennas with amplifiers in recent publications.