Aerospace and Electronic Systems Magazine June 2017 - 47

rying out research work together with other students from a research group belonging to the Faculty of Electrical Engineering
at WUT. He started his first research work and teaching activity while still a student, and from 1917 he began working as
a research assistant at the Electrical Measurement Department
of the Faculty of Electrical Engineering, WUT. In 1922 he finished his studies, obtaining an Electrical Engineering Diploma
from WUT. At the age of 24 he was the youngest lecturer to give
lectures on cathode tubes. In 1924 he became the head of the
Radio Engineering Laboratory at WUT, and the following year
he published a revolutionary monography and discussion on
"Cathode Waves and Their Use in Radiotelegraphy"-a world
first-which has since been translated into many languages from
the original Polish. The first translation, entitled "Les Lampes à
plusieures électrodes et leurs applications en radiotechnique",
was published in Paris in 1927 [1]. Professor Groszkowski received his PhD in 1928 for his work entitled "The Compensation Method for Controlling Wave Stability". In 1929 he became
the youngest associate professor at WUT, and in 1935 he received the title of full professor. In 1933, in Proceedings of the
Institute of Radio Engineers, he published an excellent work on
"The Interdependence of the Frequency Variation and Harmonic
Content and the Problem of Constant-Frequency Oscillators". It
should be mentioned that the interdependence given by the following formula [5], [11]-[15]:


1 

 2  ak  nk2 ,
2Q k  2
0

(1)

where ak being a coefficient depending on the topology of the circuit and nk = Ik/I1, where Ik is the amplitude of the k-th harmonic
of the tank current, is widely called Groszkowski's equation and
has been cited by many authors [11]-[15]. The formula (1) derived
by Groszkowski mathematically proved that the presence of harmonics in the tank current of an LC-voltage-controlled oscillator,
which is induced by the nonlinearity of the circuit, results in a shift
of the oscillation frequency from the tank resonance frequency [5],
[11]-[15].
His main area of research in the 1930s was widely known at
that time as radio-engineering [1]-[9]. To increase the effectiveness of research in this field, he established the State Telecommunications Institute in Poland (Figure 2), now known as PIT (the
present name is PIT-RADWAR) in 1935. Since then a tremendous
amount of progress in the development of applied technology in
radio-engineering has been observed in Poland.
JUNE 2017

In 1938 the total number of people employed at PIT was 350,
200 of which were researchers and engineers. The total budget was
around $240,000 USD. At that time, PIT specialized in the development of transmitting tubes, high-stability oscillators, and measuring equipment, and was responsible for the first experimental
television broadcast in Warsaw, transmitting a film on October 5,
1938. Many innovative technologies invented by Professor Groszkowski were later applied in radiolocation, the main two being

Figure 1.

Professor Janusz Groszkowski.

Figure 2.

PIT facility at Ratuszowa street in Warsaw, 1938.

IEEE A&E SYSTEMS MAGAZINE

Table of Contents for the Digital Edition of Aerospace and Electronic Systems Magazine June 2017