{'fraction_non_alphanumeric': 0.03634751773049645, 'fraction_numerical': 0.02925531914893617, 'mean_word_length': 4.730964467005077, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A Multiband Monopole Antenna With an Embedded Reactance-Cancelling Transmission-Line Matching Network

A series reactance-canceling (SERCA) transmission-line (TL) matching network is proposed, which replaces the series resonant circuit of a double-tuned Wheeler matching network with a λg/2 TL in order to achieve a broadband double-tuned matching response around the design frequency f0 while also introducing additional matching bands at harmonic frequencies of f0. The reactance cancellation property of the λg/2 TL is first outlined, followed by simple equations for the design of multiband SERCA-TL matching networks. A SERCA-TL matching network is subsequently embedded within a printed circular monopole antenna, and it is demonstrated that the lowest frequency of operation can be reduced from 4.43 GHz for the unmatched monopole to 2.1 GHz. Thus, a compact, multiband, and highly efficient antenna is achieved that operates in the frequency ranges of 2.1-4.31 and 6.35-6.78 GHz. The total size of the antenna is 20 × 50.3 × 1.59 mm3, and the measured efficiency is on the order of 80%-90% within the bands of operation.