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This paper presents a novel and accurate procedure for designing a Doherty power amplifier (DPA) for wireless systems. The method is based on a systematic approach to designing the matching networks of both Main and Auxiliary devices, which employs an optimization process to set their input impedance in the corresponding optimal regions obtained from standard load-and source-pull simulations. To import the optimum regions of each device into the optimization algorithm, mathematical expressions are derived and graphically reported on the Smith chart. Besides this, we have developed an accurate method to account for the loading effect of the Auxiliary amplifier on the Main one at back-off when designing the Main PA. As a proof of concept, a symmetric DPA is designed, fabricated, and tested. The measurements showed a working frequency band of 3.3 -3.9 GHz (aimed at n78 band of 5G-NR), a minimum peak output power of 36 W, drain efficiency between 48 % -53.2 % at peak and 34.6 % -44.5 % at 6 dB back-off.INDEX TERMS Doherty power amplifier, high-efficiency power amplifier, load-pull, optimization, sourcepull, wideband matching network.

Background: Empirical evidence and theoretical approaches suggest that rumination and cognitive dysfunction are interrelated. Individuals with high rumination often display dysfunction in different cognitive abilities such as attention and memory. In this study, we attempted to peruse how Rumination-Focused Cognitive Behavioral Therapy, which has proven effective in reducing rumination, influences different cognitive abilities. In a pretest-posttest design, the therapy group received twelve weeks of therapy while the assessment group received no treatment. We tested Attentional control, working memory, and iconic memory before and after the treatment. Results: Treatment successfully decreased rumination and significantly improved performance in the iconic memory task. Individuals who received the treatment recalled more items correctly, and the number of false recalls was reduced compared to the assessment group. No significant effect on working memory was observed, and only anecdotal evidence for enhancing attentional control function. Conclusions: Our findings demonstrate that Rumination-Focused Cognitive Behavioral Therapy can improve specific cognitive functions like memory and attention in adults with high levels of rumination.

In medical literature, studies are divided into two categories; experimental and observational settings. Experimental studies, entitled randomized controlled trials could test the relationship between exposure and outcome experimentally via control group and random allocation. Observational settings include either analytical or descriptive studies. Descriptive studies consist of case reports and case series that are helpful in present the experience of a case or a series of cases with similar diagnoses in detail which results in hypothesis generation. Cross-sectional studies, as analytical designs, are not capable to survey the temporality of exposure and outcome as simultaneously exposure and outcome status are measured. In case-control studies, subjects follow back from outcome to exposure. The rare diseases are recommended to study using case-control setting to save expenses and time. Both exposure measurement and patient selection is before disease detection in cohort studies. Therefore, they are inefficient for rare diseases or diseases with long latency. Cohort studies are time consuming with high cost and loss to follow-up. This paper elaborately reviews the features, advantages, and disadvantages of different types of observational and experimental studies.